diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index f86a36e64ae..b0a6a1825c9 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -46,6 +46,7 @@ jobs:
           nav2_loopback_sim
           nav2_map_server
           nav2_simple_commander
+          nav2_system_tests
         arguments: --config tools/pyproject.toml
 
   pre-commit:
diff --git a/nav2_system_tests/src/behaviors/assisted_teleop/test_assisted_teleop_behavior_launch.py b/nav2_system_tests/src/behaviors/assisted_teleop/test_assisted_teleop_behavior_launch.py
index 3a9556278bc..c33f1711bd2 100755
--- a/nav2_system_tests/src/behaviors/assisted_teleop/test_assisted_teleop_behavior_launch.py
+++ b/nav2_system_tests/src/behaviors/assisted_teleop/test_assisted_teleop_behavior_launch.py
@@ -27,7 +27,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -43,7 +43,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     params_file = os.path.join(nav2_bringup_dir, 'params/nav2_params.yaml')
@@ -109,10 +109,10 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
-    testExecutable = os.getenv('TEST_EXECUTABLE')
+    testExecutable = os.getenv('TEST_EXECUTABLE', '')
 
     test1_action = ExecuteProcess(
         cmd=[testExecutable], name='test_assisted_teleop_behavior_node', output='screen'
diff --git a/nav2_system_tests/src/behaviors/backup/backup_tester.py b/nav2_system_tests/src/behaviors/backup/backup_tester.py
index 711441bd4cb..bcd863cae0e 100755
--- a/nav2_system_tests/src/behaviors/backup/backup_tester.py
+++ b/nav2_system_tests/src/behaviors/backup/backup_tester.py
@@ -15,6 +15,7 @@
 
 import sys
 import time
+from typing import Optional
 
 from action_msgs.msg import GoalStatus
 from geometry_msgs.msg import Point32, PolygonStamped
@@ -22,7 +23,8 @@
 from nav2_msgs.msg import Costmap
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
+from rclpy.action.client import ClientGoalHandle
 from rclpy.duration import Duration
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
@@ -30,7 +32,7 @@
 
 class BackupTest(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__(node_name='backup_tester', namespace='')
         self.costmap_qos = QoSProfile(
             durability=QoSDurabilityPolicy.TRANSIENT_LOCAL,
@@ -43,10 +45,11 @@ def __init__(self):
             Costmap, 'local_costmap/costmap_raw', self.costmap_qos)
         self.footprint_pub = self.create_publisher(
             PolygonStamped, 'local_costmap/published_footprint', 10)
-        self.goal_handle = None
-        self.action_result = None
+        self.goal_handle: Optional[ClientGoalHandle[
+                BackUp.Goal, BackUp.Result, BackUp.Feedback]] = None
+        self.action_result = BackUp.Result()
 
-    def sendCommand(self, command):
+    def sendCommand(self, command: BackUp.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -55,7 +58,7 @@ def sendCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -65,8 +68,8 @@ def sendCommand(self, command):
         self.info_msg("Waiting for 'Backup' action to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -80,7 +83,7 @@ def sendCommand(self, command):
         self.info_msg('Backup failed to meet target!')
         return False
 
-    def sendAndPreemptWithFasterCommand(self, command):
+    def sendAndPreemptWithFasterCommand(self, command: BackUp.Goal) -> bool:
         # Send initial goal
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
@@ -90,7 +93,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -108,7 +111,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Preemption rejected')
             return False
 
@@ -119,8 +122,8 @@ def sendAndPreemptWithFasterCommand(self, command):
         self.info_msg("Waiting for 'backup' action Preemption to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -134,7 +137,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         self.info_msg('Backup failed to meet target!')
         return False
 
-    def sendAndCancelCommand(self, command):
+    def sendAndCancelCommand(self, command: BackUp.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -143,7 +146,7 @@ def sendAndCancelCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -155,7 +158,7 @@ def sendAndCancelCommand(self, command):
         cancel_future = self.goal_handle.cancel_goal_async()
         rclpy.spin_until_future_complete(self, cancel_future)
         rclpy.spin_until_future_complete(self, self.result_future)
-        status = self.result_future.result().status
+        status = self.result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_CANCELED:
             self.info_msg(f'Goal failed with status code: {status}')
             return False
@@ -163,7 +166,7 @@ def sendAndCancelCommand(self, command):
             self.info_msg('Goal was canceled successfully')
             return True
 
-    def sendFreeCostmap(self):
+    def sendFreeCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -186,7 +189,7 @@ def sendFreeCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def sendOccupiedCostmap(self):
+    def sendOccupiedCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -209,7 +212,7 @@ def sendOccupiedCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def run(self):
+    def run(self) -> bool:
         while not self.action_client.wait_for_server(timeout_sec=1.0):
             self.info_msg("'Backup' action server not available, waiting...")
 
@@ -278,7 +281,7 @@ def run(self):
             self.info_msg('Test D passed')
         return True
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
 
         self.action_client.destroy()
@@ -300,17 +303,17 @@ def shutdown(self):
 
         self.info_msg(f'{transition_service} finished')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info(msg)
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn(msg)
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
     time.sleep(10)
     test = BackupTest()
diff --git a/nav2_system_tests/src/behaviors/backup/test_backup_behavior.launch.py b/nav2_system_tests/src/behaviors/backup/test_backup_behavior.launch.py
index b7ca717286d..291dbb4b836 100755
--- a/nav2_system_tests/src/behaviors/backup/test_backup_behavior.launch.py
+++ b/nav2_system_tests/src/behaviors/backup/test_backup_behavior.launch.py
@@ -28,7 +28,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     bringup_dir = get_package_share_directory('nav2_bringup')
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     params_file = LaunchConfiguration('params_file')
@@ -133,12 +133,13 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[os.path.join(
-            os.getenv('TEST_DIR'), 'backup_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
+            os.getenv('TEST_DIR', ''),
+            'backup_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
         name='tester_node',
         output='screen',
     )
diff --git a/nav2_system_tests/src/behaviors/drive_on_heading/drive_tester.py b/nav2_system_tests/src/behaviors/drive_on_heading/drive_tester.py
index 852f3bee6a9..2f3721c1580 100755
--- a/nav2_system_tests/src/behaviors/drive_on_heading/drive_tester.py
+++ b/nav2_system_tests/src/behaviors/drive_on_heading/drive_tester.py
@@ -15,6 +15,7 @@
 
 import sys
 import time
+from typing import Optional
 
 from action_msgs.msg import GoalStatus
 from geometry_msgs.msg import Point32, PolygonStamped
@@ -22,7 +23,8 @@
 from nav2_msgs.msg import Costmap
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
+from rclpy.action.client import ClientGoalHandle
 from rclpy.duration import Duration
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
@@ -30,7 +32,7 @@
 
 class DriveTest(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__(node_name='drive_tester', namespace='')
         self.costmap_qos = QoSProfile(
             durability=QoSDurabilityPolicy.TRANSIENT_LOCAL,
@@ -43,10 +45,12 @@ def __init__(self):
             Costmap, 'local_costmap/costmap_raw', self.costmap_qos)
         self.footprint_pub = self.create_publisher(
             PolygonStamped, 'local_costmap/published_footprint', 10)
-        self.goal_handle = None
-        self.action_result = None
+        self.goal_handle: Optional[ClientGoalHandle[
+                DriveOnHeading.Goal, DriveOnHeading.Result,
+                DriveOnHeading.Feedback]] = None
+        self.action_result = DriveOnHeading.Result()
 
-    def sendCommand(self, command):
+    def sendCommand(self, command: DriveOnHeading.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -55,7 +59,7 @@ def sendCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -65,8 +69,8 @@ def sendCommand(self, command):
         self.info_msg("Waiting for 'DriveOnHeading' action to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -80,7 +84,7 @@ def sendCommand(self, command):
         self.info_msg('DriveOnHeading failed to meet target!')
         return False
 
-    def sendAndPreemptWithFasterCommand(self, command):
+    def sendAndPreemptWithFasterCommand(self, command: DriveOnHeading.Goal) -> bool:
         # Send initial goal
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
@@ -90,7 +94,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -108,7 +112,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Preemption rejected')
             return False
 
@@ -119,8 +123,8 @@ def sendAndPreemptWithFasterCommand(self, command):
         self.info_msg("Waiting for 'DriveOnHeading' action Preemption to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -134,7 +138,7 @@ def sendAndPreemptWithFasterCommand(self, command):
         self.info_msg('DriveOnHeading failed to meet target!')
         return False
 
-    def sendAndCancelCommand(self, command):
+    def sendAndCancelCommand(self, command: DriveOnHeading.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -143,7 +147,7 @@ def sendAndCancelCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -155,7 +159,7 @@ def sendAndCancelCommand(self, command):
         cancel_future = self.goal_handle.cancel_goal_async()
         rclpy.spin_until_future_complete(self, cancel_future)
         rclpy.spin_until_future_complete(self, self.result_future)
-        status = self.result_future.result().status
+        status = self.result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_CANCELED:
             self.info_msg(f'Goal failed with status code: {status}')
             return False
@@ -163,7 +167,7 @@ def sendAndCancelCommand(self, command):
             self.info_msg('Goal was canceled successfully')
             return True
 
-    def sendFreeCostmap(self):
+    def sendFreeCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -186,7 +190,7 @@ def sendFreeCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def sendOccupiedCostmap(self):
+    def sendOccupiedCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -209,7 +213,7 @@ def sendOccupiedCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def run(self):
+    def run(self) -> bool:
         while not self.action_client.wait_for_server(timeout_sec=1.0):
             self.info_msg("'DriveOnHeading' action server not available, waiting...")
 
@@ -286,7 +290,7 @@ def run(self):
             self.info_msg('Test D passed')
         return True
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
 
         self.action_client.destroy()
@@ -308,17 +312,17 @@ def shutdown(self):
 
         self.info_msg(f'{transition_service} finished')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info(msg)
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn(msg)
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
     time.sleep(10)
     test = DriveTest()
diff --git a/nav2_system_tests/src/behaviors/drive_on_heading/test_drive_on_heading_behavior.launch.py b/nav2_system_tests/src/behaviors/drive_on_heading/test_drive_on_heading_behavior.launch.py
index 2b308537f1d..016d9ef163f 100755
--- a/nav2_system_tests/src/behaviors/drive_on_heading/test_drive_on_heading_behavior.launch.py
+++ b/nav2_system_tests/src/behaviors/drive_on_heading/test_drive_on_heading_behavior.launch.py
@@ -28,7 +28,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     bringup_dir = get_package_share_directory('nav2_bringup')
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     params_file = LaunchConfiguration('params_file')
@@ -133,12 +133,13 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[os.path.join(
-            os.getenv('TEST_DIR'), 'drive_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
+            os.getenv('TEST_DIR', ''),
+            'drive_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
         name='tester_node',
         output='screen',
     )
diff --git a/nav2_system_tests/src/behaviors/spin/spin_tester.py b/nav2_system_tests/src/behaviors/spin/spin_tester.py
index 917df80aeb9..ff5087e62ed 100755
--- a/nav2_system_tests/src/behaviors/spin/spin_tester.py
+++ b/nav2_system_tests/src/behaviors/spin/spin_tester.py
@@ -15,6 +15,7 @@
 
 import sys
 import time
+from typing import Optional
 
 from action_msgs.msg import GoalStatus
 from geometry_msgs.msg import Point32, PolygonStamped
@@ -22,7 +23,8 @@
 from nav2_msgs.msg import Costmap
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
+from rclpy.action.client import ClientGoalHandle
 from rclpy.duration import Duration
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
@@ -30,7 +32,7 @@
 
 class SpinTest(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__(node_name='spin_tester', namespace='')
         self.costmap_qos = QoSProfile(
             durability=QoSDurabilityPolicy.TRANSIENT_LOCAL,
@@ -43,10 +45,11 @@ def __init__(self):
             Costmap, 'local_costmap/costmap_raw', self.costmap_qos)
         self.footprint_pub = self.create_publisher(
             PolygonStamped, 'local_costmap/published_footprint', 10)
-        self.goal_handle = None
-        self.action_result = None
+        self.goal_handle: Optional[ClientGoalHandle[
+                Spin.Goal, Spin.Result, Spin.Feedback]] = None
+        self.action_result = Spin.Result()
 
-    def sendCommand(self, command):
+    def sendCommand(self, command: Spin.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -55,7 +58,7 @@ def sendCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -65,8 +68,8 @@ def sendCommand(self, command):
         self.info_msg("Waiting for 'spin' action to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -80,7 +83,7 @@ def sendCommand(self, command):
         self.info_msg('Spin failed to meet target!')
         return False
 
-    def sendAndPreemptWithInvertedCommand(self, command):
+    def sendAndPreemptWithInvertedCommand(self, command: Spin.Goal) -> bool:
         # Send initial goal
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
@@ -90,7 +93,7 @@ def sendAndPreemptWithInvertedCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -108,7 +111,7 @@ def sendAndPreemptWithInvertedCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Preemption rejected')
             return False
 
@@ -119,8 +122,8 @@ def sendAndPreemptWithInvertedCommand(self, command):
         self.info_msg("Waiting for 'spin' action Preemption to complete")
         try:
             rclpy.spin_until_future_complete(self, self.result_future)
-            status = self.result_future.result().status
-            result = self.result_future.result().result
+            status = self.result_future.result().status  # type: ignore[union-attr]
+            result = self.result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -134,7 +137,7 @@ def sendAndPreemptWithInvertedCommand(self, command):
         self.info_msg('Spin failed to meet target!')
         return False
 
-    def sendAndCancelCommand(self, command):
+    def sendAndCancelCommand(self, command: Spin.Goal) -> bool:
         self.info_msg('Sending goal request...')
         self.goal_future = self.action_client.send_goal_async(command)
         try:
@@ -143,7 +146,7 @@ def sendAndCancelCommand(self, command):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -155,7 +158,7 @@ def sendAndCancelCommand(self, command):
         cancel_future = self.goal_handle.cancel_goal_async()
         rclpy.spin_until_future_complete(self, cancel_future)
         rclpy.spin_until_future_complete(self, self.result_future)
-        status = self.result_future.result().status
+        status = self.result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_CANCELED:
             self.info_msg(f'Goal failed with status code: {status}')
             return False
@@ -163,7 +166,7 @@ def sendAndCancelCommand(self, command):
             self.info_msg('Goal was canceled successfully')
             return True
 
-    def sendFreeCostmap(self):
+    def sendFreeCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -186,7 +189,7 @@ def sendFreeCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def sendOccupiedCostmap(self):
+    def sendOccupiedCostmap(self) -> None:
         costmap_msg = Costmap()
         costmap_msg.header.frame_id = 'odom'
         costmap_msg.header.stamp = self.get_clock().now().to_msg()
@@ -209,7 +212,7 @@ def sendOccupiedCostmap(self):
         ]
         self.footprint_pub.publish(footprint_msg)
 
-    def run(self):
+    def run(self) -> bool:
         while not self.action_client.wait_for_server(timeout_sec=1.0):
             self.info_msg("'spin' action server not available, waiting...")
 
@@ -270,7 +273,7 @@ def run(self):
             self.info_msg('Test D passed')
         return True
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
 
         self.action_client.destroy()
@@ -292,17 +295,17 @@ def shutdown(self):
 
         self.info_msg(f'{transition_service} finished')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info(msg)
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn(msg)
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
     time.sleep(10)
     test = SpinTest()
diff --git a/nav2_system_tests/src/behaviors/spin/test_spin_behavior.launch.py b/nav2_system_tests/src/behaviors/spin/test_spin_behavior.launch.py
index 38c205c6508..cadef8c367a 100755
--- a/nav2_system_tests/src/behaviors/spin/test_spin_behavior.launch.py
+++ b/nav2_system_tests/src/behaviors/spin/test_spin_behavior.launch.py
@@ -28,7 +28,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     bringup_dir = get_package_share_directory('nav2_bringup')
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     params_file = LaunchConfiguration('params_file')
@@ -133,12 +133,13 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[os.path.join(
-            os.getenv('TEST_DIR'), 'spin_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
+            os.getenv('TEST_DIR', ''),
+            'spin_tester.py'), '--ros-args', '-p', 'use_sim_time:=True'],
         name='tester_node',
         output='screen',
     )
diff --git a/nav2_system_tests/src/behaviors/wait/test_wait_behavior_launch.py b/nav2_system_tests/src/behaviors/wait/test_wait_behavior_launch.py
index da70e9b04da..49cee4ea48e 100755
--- a/nav2_system_tests/src/behaviors/wait/test_wait_behavior_launch.py
+++ b/nav2_system_tests/src/behaviors/wait/test_wait_behavior_launch.py
@@ -28,7 +28,7 @@
 from nav2_simple_commander.utils import kill_os_processes
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
     ros_gz_sim_dir = get_package_share_directory('ros_gz_sim')
@@ -45,7 +45,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     bringup_dir = get_package_share_directory('nav2_bringup')
@@ -114,10 +114,10 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
-    testExecutable = os.getenv('TEST_EXECUTABLE')
+    testExecutable = os.getenv('TEST_EXECUTABLE', '')
 
     test1_action = ExecuteProcess(
         cmd=[testExecutable], name='test_wait_behavior_node', output='screen',
diff --git a/nav2_system_tests/src/costmap_filters/test_keepout_launch.py b/nav2_system_tests/src/costmap_filters/test_keepout_launch.py
index ff554956e8f..71d4189994a 100755
--- a/nav2_system_tests/src/costmap_filters/test_keepout_launch.py
+++ b/nav2_system_tests/src/costmap_filters/test_keepout_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
     nav2_sys_test_dir = get_package_share_directory('nav2_system_tests')
@@ -43,12 +43,12 @@ def generate_launch_description():
         robot_description = infp.read()
 
     map_yaml_file = os.path.join(nav2_sys_test_dir, 'maps', 'map_circular.yaml')
-    filter_mask_file = os.getenv('TEST_MASK')
+    filter_mask_file = os.getenv('TEST_MASK', '')
 
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     script_dir = os.path.dirname(os.path.realpath(__file__))
@@ -164,12 +164,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), 'tester_node.py'),
+            os.path.join(os.getenv('TEST_DIR', ''), 'tester_node.py'),
             '-t',
             'keepout',
             '-r',
diff --git a/nav2_system_tests/src/costmap_filters/test_speed_launch.py b/nav2_system_tests/src/costmap_filters/test_speed_launch.py
index 31c55ccc9db..8746c7c7266 100755
--- a/nav2_system_tests/src/costmap_filters/test_speed_launch.py
+++ b/nav2_system_tests/src/costmap_filters/test_speed_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
     nav2_sys_test_dir = get_package_share_directory('nav2_system_tests')
@@ -48,10 +48,10 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
-    params_file = os.getenv('PARAMS_FILE')
+    params_file = os.getenv('PARAMS_FILE', '')
 
     # Replace the `use_astar` setting on the params file
     param_substitutions = {
@@ -155,12 +155,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), 'tester_node.py'),
+            os.path.join(os.getenv('TEST_DIR', ''), 'tester_node.py'),
             '-t',
             'speed',
             '-r',
diff --git a/nav2_system_tests/src/costmap_filters/tester_node.py b/nav2_system_tests/src/costmap_filters/tester_node.py
index c978e570b13..0f80d146fe6 100755
--- a/nav2_system_tests/src/costmap_filters/tester_node.py
+++ b/nav2_system_tests/src/costmap_filters/tester_node.py
@@ -30,7 +30,7 @@
 from nav2_msgs.srv import ManageLifecycleNodes
 from nav_msgs.msg import OccupancyGrid, Path
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
 from sensor_msgs.msg import PointCloud2
@@ -44,12 +44,12 @@ class TestType(Enum):
 class FilterMask:
 
     def __init__(self, filter_mask: OccupancyGrid):
-        self.filter_mask = filter_mask
+        self.filter_mask: OccupancyGrid = filter_mask
 
     # Converts world coordinates into filter mask map coordinate.
     # Returns filter mask map coordinates or (-1, -1) in case
     # if world coordinates are out of mask bounds.
-    def worldToMap(self, wx: float, wy: float):
+    def worldToMap(self, wx: float, wy: float) -> tuple[int, int]:
         origin_x = self.filter_mask.info.origin.position.x
         origin_y = self.filter_mask.info.origin.position.y
         size_x = self.filter_mask.info.width
@@ -68,7 +68,7 @@ def worldToMap(self, wx: float, wy: float):
         return -1, -1
 
     # Gets filter_mask[mx, my] value
-    def getValue(self, mx, my):
+    def getValue(self, mx: int, my: int):  # type: ignore[no-untyped-def]
         size_x = self.filter_mask.info.width
         return self.filter_mask.data[mx + my * size_x]
 
@@ -95,9 +95,9 @@ def __init__(
         )
 
         volatile_qos = QoSProfile(
-            durability=QoSDurabilityPolicy.RMW_QOS_POLICY_DURABILITY_VOLATILE,
+            durability=QoSDurabilityPolicy.VOLATILE,
             reliability=QoSReliabilityPolicy.RELIABLE,
-            history=QoSHistoryPolicy.RMW_QOS_POLICY_HISTORY_KEEP_LAST,
+            history=QoSHistoryPolicy.KEEP_LAST,
             depth=1,
         )
 
@@ -153,16 +153,16 @@ def __init__(
         self.goal_pose = goal_pose
         self.action_client = ActionClient(self, NavigateToPose, 'navigate_to_pose')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info('\033[1;37;44m' + msg + '\033[0m')
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn('\033[1;37;43m' + msg + '\033[0m')
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error('\033[1;37;41m' + msg + '\033[0m')
 
-    def setInitialPose(self):
+    def setInitialPose(self) -> None:
         msg = PoseWithCovarianceStamped()
         msg.pose.pose = self.initial_pose
         msg.header.frame_id = 'map'
@@ -170,17 +170,17 @@ def setInitialPose(self):
         self.initial_pose_pub.publish(msg)
         self.currentPose = self.initial_pose
 
-    def getStampedPoseMsg(self, pose: Pose):
+    def getStampedPoseMsg(self, pose: Pose) -> PoseStamped:
         msg = PoseStamped()
         msg.header.frame_id = 'map'
         msg.pose = pose
         return msg
 
-    def publishGoalPose(self, goal_pose: Optional[Pose] = None):
+    def publishGoalPose(self, goal_pose: Optional[Pose] = None) -> None:
         self.goal_pose = goal_pose if goal_pose is not None else self.goal_pose
         self.goal_pub.publish(self.getStampedPoseMsg(self.goal_pose))
 
-    def runNavigateAction(self, goal_pose: Optional[Pose] = None):
+    def runNavigateAction(self, goal_pose: Optional[Pose] = None) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateToPose' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -196,7 +196,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -205,7 +205,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
             self.info_msg(f'Goal failed with status code: {status}')
             return False
@@ -213,7 +213,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         self.info_msg('Goal succeeded!')
         return True
 
-    def isInKeepout(self, x, y):
+    def isInKeepout(self, x: float, y: float) -> bool:
         mx, my = self.filter_mask.worldToMap(x, y)
         if mx == -1 and my == -1:  # Out of mask's area
             return False
@@ -222,7 +222,7 @@ def isInKeepout(self, x, y):
         return False
 
     # Checks that (x, y) position does not belong to a keepout zone.
-    def checkKeepout(self, x, y):
+    def checkKeepout(self, x: float, y: float) -> bool:
         if not self.mask_received:
             self.warn_msg('Filter mask was not received')
         elif self.isInKeepout(x, y):
@@ -238,7 +238,7 @@ def checkKeepout(self, x, y):
     # Also verifies that speed limit messages received no more than N-times
     # (where N - is the length of 'limits' array),
     # otherwise sets overall 'filter_test_result' to be false.
-    def checkSpeed(self, it, speed_limit):
+    def checkSpeed(self, it: int, speed_limit: float) -> None:
         if it >= len(self.limits):
             self.error_msg('Got excess speed limit')
             self.filter_test_result = False
@@ -253,7 +253,7 @@ def checkSpeed(self, it, speed_limit):
                 + str(self.limits[it])
             )
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.current_pose = msg.pose.pose
         self.initial_pose_received = True
@@ -263,41 +263,41 @@ def poseCallback(self, msg):
             ):
                 self.error_msg('Robot goes into keepout zone')
 
-    def planCallback(self, msg):
+    def planCallback(self, msg: Path) -> None:
         self.info_msg('Received plan')
         for pose in msg.poses:
             if not self.checkKeepout(pose.pose.position.x, pose.pose.position.y):
                 self.error_msg('Path plan intersects with keepout zone')
                 return
 
-    def clearingEndpointsCallback(self, msg):
+    def clearingEndpointsCallback(self, msg: PointCloud2) -> None:
         if len(msg.data) > 0:
             self.clearing_endpoints_received = True
 
-    def voxelMarkedCallback(self, msg):
+    def voxelMarkedCallback(self, msg: PointCloud2) -> None:
         if len(msg.data) > 0:
             self.voxel_marked_received = True
 
-    def voxelUnknownCallback(self, msg):
+    def voxelUnknownCallback(self, msg: PointCloud2) -> None:
         if len(msg.data) > 0:
             self.voxel_unknown_received = True
 
-    def dwbCostCloudCallback(self, msg):
+    def dwbCostCloudCallback(self, msg: PointCloud2) -> None:
         self.info_msg('Received cost_cloud points')
         if len(msg.data) > 0:
             self.cost_cloud_received = True
 
-    def speedLimitCallback(self, msg):
+    def speedLimitCallback(self, msg: SpeedLimit) -> None:
         self.info_msg(f'Received speed limit: {msg.speed_limit}')
         self.checkSpeed(self.speed_it, msg.speed_limit)
         self.speed_it += 1
 
-    def maskCallback(self, msg):
+    def maskCallback(self, msg: OccupancyGrid) -> None:
         self.info_msg('Received filter mask')
         self.filter_mask = FilterMask(msg)
         self.mask_received = True
 
-    def wait_for_filter_mask(self, timeout):
+    def wait_for_filter_mask(self, timeout: float) -> bool:
         start_time = time.time()
 
         while not self.mask_received:
@@ -308,7 +308,7 @@ def wait_for_filter_mask(self, timeout):
                 return False
         return True
 
-    def wait_for_pointcloud_subscribers(self, timeout):
+    def wait_for_pointcloud_subscribers(self, timeout: float) -> bool:
         start_time = time.time()
         while (
             not self.voxel_unknown_received
@@ -328,7 +328,7 @@ def wait_for_pointcloud_subscribers(self, timeout):
                 return False
         return True
 
-    def reachesGoal(self, timeout, distance):
+    def reachesGoal(self, timeout: float, distance: float) -> bool:
         goalReached = False
         start_time = time.time()
 
@@ -343,14 +343,17 @@ def reachesGoal(self, timeout, distance):
                     self.error_msg('Robot timed out reaching its goal!')
                     return False
 
-    def distanceFromGoal(self):
+        self.info_msg('Robot reached its goal!')
+        return True
+
+    def distanceFromGoal(self) -> float:
         d_x = self.current_pose.position.x - self.goal_pose.position.x
         d_y = self.current_pose.position.y - self.goal_pose.position.y
         distance = math.sqrt(d_x * d_x + d_y * d_y)
         self.info_msg(f'Distance from goal is: {distance}')
         return distance
 
-    def wait_for_node_active(self, node_name: str):
+    def wait_for_node_active(self, node_name: str) -> None:
         # Waits for the node within the tester namespace to become active
         self.info_msg(f'Waiting for {node_name} to become active')
         node_service = f'{node_name}/get_state'
@@ -364,15 +367,15 @@ def wait_for_node_active(self, node_name: str):
             future = state_client.call_async(req)
             rclpy.spin_until_future_complete(self, future)
             if future.result() is not None:
-                state = future.result().current_state.label
+                state = future.result().current_state.label  # type: ignore[union-attr]
                 self.info_msg(f'Result of get_state: {state}')
             else:
                 self.error_msg(
-                    'Exception while calling service: %r' % future.exception()
+                    f'Exception while calling service: {future.exception()!r}'
                 )
             time.sleep(5)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
         self.action_client.destroy()
 
@@ -407,7 +410,7 @@ def shutdown(self):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-    def wait_for_initial_pose(self):
+    def wait_for_initial_pose(self) -> None:
         self.initial_pose_received = False
         while not self.initial_pose_received:
             self.info_msg('Setting initial pose')
@@ -416,7 +419,7 @@ def wait_for_initial_pose(self):
             rclpy.spin_once(self, timeout_sec=1)
 
 
-def test_RobotMovesToGoal(robot_tester):
+def test_RobotMovesToGoal(robot_tester: NavTester) -> bool:
     robot_tester.info_msg('Setting goal pose')
     robot_tester.publishGoalPose()
     robot_tester.info_msg('Waiting 60 seconds for robot to reach goal')
@@ -428,7 +431,7 @@ def test_RobotMovesToGoal(robot_tester):
 # checks that all items in 'limit_passed' permissive array are also true.
 # In other words, it verifies that all speed limits are received
 # exactly (by count and values) as expected by 'limits' array.
-def test_SpeedLimitsAllCorrect(robot_tester):
+def test_SpeedLimitsAllCorrect(robot_tester: NavTester) -> bool:
     if not robot_tester.filter_test_result:
         return False
     for passed in robot_tester.limit_passed:
@@ -438,7 +441,7 @@ def test_SpeedLimitsAllCorrect(robot_tester):
     return True
 
 
-def run_all_tests(robot_tester):
+def run_all_tests(robot_tester: NavTester) -> bool:
     # set transforms to use_sim_time
     result = True
     if result:
@@ -472,7 +475,7 @@ def run_all_tests(robot_tester):
     return result
 
 
-def fwd_pose(x=0.0, y=0.0, z=0.01):
+def fwd_pose(x: float = 0.0, y: float = 0.0, z: float = 0.01) -> Pose:
     initial_pose = Pose()
     initial_pose.position.x = x
     initial_pose.position.y = y
@@ -484,7 +487,7 @@ def fwd_pose(x=0.0, y=0.0, z=0.01):
     return initial_pose
 
 
-def get_tester(args):
+def get_tester(args: argparse.Namespace) -> NavTester:
 
     # Requested tester for one robot
     type_str = args.type
@@ -512,7 +515,7 @@ def get_tester(args):
     return tester
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     # The robot(s) positions from the input arguments
     parser = argparse.ArgumentParser(
         description='System-level costmap filters tester node'
diff --git a/nav2_system_tests/src/error_codes/test_error_codes.py b/nav2_system_tests/src/error_codes/test_error_codes.py
index 24ce673726a..f46819ef7aa 100755
--- a/nav2_system_tests/src/error_codes/test_error_codes.py
+++ b/nav2_system_tests/src/error_codes/test_error_codes.py
@@ -24,7 +24,7 @@
 import rclpy
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
 
     navigator = BasicNavigator()
@@ -113,7 +113,7 @@ def main(argv=sys.argv[1:]):
             result.error_msg != ''
         ), 'Compute path to pose error_msg empty'
 
-    def cancel_task():
+    def cancel_task() -> None:
         time.sleep(1)
         navigator.goal_handle.cancel_goal_async()
 
@@ -174,7 +174,7 @@ def cancel_task():
     a_path.poses.append(pose1)
 
     navigator._waitForNodeToActivate('smoother_server')
-    smoother = {
+    smoother_errors = {
         'invalid_smoother': SmoothPath.Result().INVALID_SMOOTHER,
         'unknown': SmoothPath.Result().UNKNOWN,
         'timeout': SmoothPath.Result().TIMEOUT,
@@ -183,7 +183,7 @@ def cancel_task():
         'invalid_path': SmoothPath.Result().INVALID_PATH,
     }
 
-    for smoother, error_code in smoother.items():
+    for smoother, error_code in smoother_errors.items():
         result = navigator._smoothPathImpl(a_path, smoother)
         assert result.error_code == error_code, 'Smoother error does not match'
         assert result.error_msg != '', 'Smoother error_msg is empty'
diff --git a/nav2_system_tests/src/error_codes/test_error_codes_launch.py b/nav2_system_tests/src/error_codes/test_error_codes_launch.py
index 3ca61767624..7e33c5bb240 100755
--- a/nav2_system_tests/src/error_codes/test_error_codes_launch.py
+++ b/nav2_system_tests/src/error_codes/test_error_codes_launch.py
@@ -22,8 +22,8 @@
 from launch_testing.legacy import LaunchTestService
 
 
-def generate_launch_description():
-    params_file = os.path.join(os.getenv('TEST_DIR'), 'error_code_param.yaml')
+def generate_launch_description() -> LaunchDescription:
+    params_file = os.path.join(os.getenv('TEST_DIR', ''), 'error_code_param.yaml')
 
     remappings = [('/tf', 'tf'), ('/tf_static', 'tf_static')]
 
@@ -103,11 +103,11 @@ def generate_launch_description():
     return ld
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test_error_codes_action = ExecuteProcess(
-        cmd=[os.path.join(os.getenv('TEST_DIR'), 'test_error_codes.py')],
+        cmd=[os.path.join(os.getenv('TEST_DIR', ''), 'test_error_codes.py')],
         name='test_error_codes',
         output='screen',
     )
diff --git a/nav2_system_tests/src/gps_navigation/dual_ekf_navsat.launch.py b/nav2_system_tests/src/gps_navigation/dual_ekf_navsat.launch.py
index 8cc64ec69e1..4705cd77bf2 100644
--- a/nav2_system_tests/src/gps_navigation/dual_ekf_navsat.launch.py
+++ b/nav2_system_tests/src/gps_navigation/dual_ekf_navsat.launch.py
@@ -18,7 +18,7 @@
 import launch_ros.actions
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     launch_dir = os.path.dirname(os.path.realpath(__file__))
     params_file = os.path.join(launch_dir, 'dual_ekf_navsat_params.yaml')
     os.environ['FILE_PATH'] = str(launch_dir)
diff --git a/nav2_system_tests/src/gps_navigation/test_case_py.launch.py b/nav2_system_tests/src/gps_navigation/test_case_py.launch.py
index ef42a91e4b7..140be5ab708 100755
--- a/nav2_system_tests/src/gps_navigation/test_case_py.launch.py
+++ b/nav2_system_tests/src/gps_navigation/test_case_py.launch.py
@@ -27,7 +27,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -110,11 +110,11 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
-        cmd=[os.path.join(os.getenv('TEST_DIR'), 'tester.py')],
+        cmd=[os.path.join(os.getenv('TEST_DIR', ''), 'tester.py')],
         name='tester_node',
         output='screen',
     )
diff --git a/nav2_system_tests/src/gps_navigation/tester.py b/nav2_system_tests/src/gps_navigation/tester.py
index 6829dc6a494..56c99324b29 100755
--- a/nav2_system_tests/src/gps_navigation/tester.py
+++ b/nav2_system_tests/src/gps_navigation/tester.py
@@ -15,6 +15,7 @@
 
 import sys
 import time
+from typing import Optional
 
 from action_msgs.msg import GoalStatus
 from geographic_msgs.msg import GeoPose
@@ -22,27 +23,30 @@
 from nav2_msgs.srv import ManageLifecycleNodes
 from rcl_interfaces.srv import SetParameters
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
+from rclpy.action.client import ClientGoalHandle
 from rclpy.node import Node
 from rclpy.parameter import Parameter
 
 
 class GpsWaypointFollowerTest(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__(node_name='nav2_gps_waypoint_tester', namespace='')
-        self.waypoints = None
+        self.waypoints: list[float] = []
         self.action_client = ActionClient(
             self, FollowGPSWaypoints, 'follow_gps_waypoints'
         )
-        self.goal_handle = None
-        self.action_result = None
+        self.goal_handle: Optional[ClientGoalHandle[
+                FollowGPSWaypoints.Goal, FollowGPSWaypoints.Result,
+                FollowGPSWaypoints.Feedback]] = None
+        self.action_result = FollowGPSWaypoints.Result()
 
         self.param_cli = self.create_client(
             SetParameters, '/waypoint_follower/set_parameters'
         )
 
-    def setWaypoints(self, waypoints):
+    def setWaypoints(self, waypoints: list[list[float]]) -> None:
         self.waypoints = []
         for wp in waypoints:
             msg = GeoPose()
@@ -51,7 +55,7 @@ def setWaypoints(self, waypoints):
             msg.orientation.w = 1.0
             self.waypoints.append(msg)
 
-    def run(self, block, cancel):
+    def run(self, block: bool, cancel: bool) -> bool:
         # if not self.waypoints:
         #     rclpy.error_msg('Did not set valid waypoints before running test!')
         #     return False
@@ -72,7 +76,7 @@ def run(self, block, cancel):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -88,8 +92,8 @@ def run(self, block, cancel):
         self.info_msg("Waiting for 'follow_gps_waypoints' action to complete")
         try:
             rclpy.spin_until_future_complete(self, get_result_future)
-            status = get_result_future.result().status
-            result = get_result_future.result().result
+            status = get_result_future.result().status  # type: ignore[union-attr]
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -100,14 +104,14 @@ def run(self, block, cancel):
         if len(result.missed_waypoints) > 0:
             self.info_msg(
                 'Goal failed to process all waypoints,'
-                ' missed {0} wps.'.format(len(result.missed_waypoints))
+                f' missed {len(result.missed_waypoints)} wps.'
             )
             return False
 
         self.info_msg('Goal succeeded!')
         return True
 
-    def setStopFailureParam(self, value):
+    def setStopFailureParam(self, value: bool) -> None:
         req = SetParameters.Request()
         req.parameters = [
             Parameter('stop_on_failure', Parameter.Type.BOOL, value).to_parameter_msg()
@@ -115,7 +119,7 @@ def setStopFailureParam(self, value):
         future = self.param_cli.call_async(req)
         rclpy.spin_until_future_complete(self, future)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
 
         self.action_client.destroy()
@@ -137,21 +141,21 @@ def shutdown(self):
 
         self.info_msg(f'{transition_service} finished')
 
-    def cancel_goal(self):
-        cancel_future = self.goal_handle.cancel_goal_async()
+    def cancel_goal(self) -> None:
+        cancel_future = self.goal_handle.cancel_goal_async()  # type: ignore[union-attr]
         rclpy.spin_until_future_complete(self, cancel_future)
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info(msg)
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn(msg)
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
 
     # wait a few seconds to make sure entire stacks are up
diff --git a/nav2_system_tests/src/localization/test_localization_launch.py b/nav2_system_tests/src/localization/test_localization_launch.py
index 1520ac09bbe..c573f39dd56 100755
--- a/nav2_system_tests/src/localization/test_localization_launch.py
+++ b/nav2_system_tests/src/localization/test_localization_launch.py
@@ -26,8 +26,8 @@
 from launch_testing.legacy import LaunchTestService
 
 
-def main(argv=sys.argv[1:]):
-    testExecutable = os.getenv('TEST_EXECUTABLE')
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
+    testExecutable = os.getenv('TEST_EXECUTABLE', '')
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
diff --git a/nav2_system_tests/src/planning/test_planner_costmaps_launch.py b/nav2_system_tests/src/planning/test_planner_costmaps_launch.py
index fd8cadb4f9d..6eb5888e80f 100755
--- a/nav2_system_tests/src/planning/test_planner_costmaps_launch.py
+++ b/nav2_system_tests/src/planning/test_planner_costmaps_launch.py
@@ -22,7 +22,7 @@
 from launch_testing.legacy import LaunchTestService
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     testExecutable = os.getenv('TEST_EXECUTABLE')
 
     ld = LaunchDescription([])
diff --git a/nav2_system_tests/src/planning/test_planner_random_launch.py b/nav2_system_tests/src/planning/test_planner_random_launch.py
index 105063110f8..ca014d6a59f 100755
--- a/nav2_system_tests/src/planning/test_planner_random_launch.py
+++ b/nav2_system_tests/src/planning/test_planner_random_launch.py
@@ -22,7 +22,7 @@
 from launch_testing.legacy import LaunchTestService
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     testExecutable = os.getenv('TEST_EXECUTABLE')
 
     ld = LaunchDescription([])
diff --git a/nav2_system_tests/src/system/nav_through_poses_tester_error_msg_node.py b/nav2_system_tests/src/system/nav_through_poses_tester_error_msg_node.py
index f24729cd79d..c170d91338a 100755
--- a/nav2_system_tests/src/system/nav_through_poses_tester_error_msg_node.py
+++ b/nav2_system_tests/src/system/nav_through_poses_tester_error_msg_node.py
@@ -75,16 +75,16 @@ def __init__(self, initial_pose: Pose, goal_pose: Pose, namespace: str = ''):
             SetParameters, '/controller_server/set_parameters'
         )
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info('\033[1;37;44m' + msg + '\033[0m')
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warning('\033[1;37;43m' + msg + '\033[0m')
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error('\033[1;37;41m' + msg + '\033[0m')
 
-    def setInitialPose(self):
+    def setInitialPose(self) -> None:
         msg = PoseWithCovarianceStamped()
         msg.pose.pose = self.initial_pose
         msg.header.frame_id = 'map'
@@ -92,17 +92,17 @@ def setInitialPose(self):
         self.initial_pose_pub.publish(msg)
         self.currentPose = self.initial_pose
 
-    def setGoalChecker(self, name):
+    def setGoalChecker(self, name: str) -> None:
         msg = String()
         msg.data = name
         self.goal_checker_selector_pub.publish(msg)
 
-    def setProgressChecker(self, name):
+    def setProgressChecker(self, name: str) -> None:
         msg = String()
         msg.data = name
         self.progress_checker_selector_pub.publish(msg)
 
-    def setControllerParam(self, name, parameter_type, value):
+    def setControllerParam(self, name: str, parameter_type: Parameter.Type, value: float) -> None:
         req = SetParameters.Request()
         req.parameters = [
             Parameter(name, parameter_type, value).to_parameter_msg()
@@ -110,7 +110,7 @@ def setControllerParam(self, name, parameter_type, value):
         future = self.controller_param_cli.call_async(req)
         rclpy.spin_until_future_complete(self, future)
 
-    def getStampedPoseMsg(self, pose: Pose):
+    def getStampedPoseMsg(self, pose: Pose) -> PoseStamped:
         msg = PoseStamped()
         msg.header.frame_id = 'map'
         msg.pose = pose
@@ -120,7 +120,7 @@ def runNavigateAction(self,
                           goal_pose: Optional[Pose] = None,
                           behavior_tree: Optional[str] = None,
                           expected_error_code: Optional[int] = None,
-                          expected_error_msg: Optional[str] = None):
+                          expected_error_msg: Optional[str] = None) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateThroughPoses' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -153,9 +153,9 @@ def runNavigateAction(self,
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
-            result = get_result_future.result().result
+            result = get_result_future.result().result  # type: ignore[union-attr]
             if (result.error_code == expected_error_code and
                result.error_msg == expected_error_msg):
                 self.info_msg(f'Goal failed as expected with status code: {status}'
@@ -173,12 +173,12 @@ def runNavigateAction(self,
         self.info_msg('Goal succeeded!')
         return True
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.current_pose = msg.pose.pose
         self.initial_pose_received = True
 
-    def wait_for_node_active(self, node_name: str):
+    def wait_for_node_active(self, node_name: str) -> None:
         # Waits for the node within the tester namespace to become active
         self.info_msg(f'Waiting for {node_name} to become active')
         node_service = f'{node_name}/get_state'
@@ -192,7 +192,7 @@ def wait_for_node_active(self, node_name: str):
             future = state_client.call_async(req)
             rclpy.spin_until_future_complete(self, future)
             if future.result() is not None:
-                state = future.result().current_state.label
+                state = future.result().current_state.label  # type: ignore[union-attr]
                 self.info_msg(f'Result of get_state: {state}')
             else:
                 self.error_msg(
@@ -200,7 +200,7 @@ def wait_for_node_active(self, node_name: str):
                 )
             time.sleep(5)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
         self.action_client.destroy()
 
@@ -235,7 +235,7 @@ def shutdown(self):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-    def wait_for_initial_pose(self):
+    def wait_for_initial_pose(self) -> None:
         self.initial_pose_received = False
         while not self.initial_pose_received:
             self.info_msg('Setting initial pose')
@@ -244,7 +244,7 @@ def wait_for_initial_pose(self):
             rclpy.spin_once(self, timeout_sec=1)
 
 
-def run_all_tests(robot_tester):
+def run_all_tests(robot_tester: NavTester) -> bool:
     pose_out_of_bounds = Pose()
     pose_out_of_bounds.position.x = 2000.0
     pose_out_of_bounds.position.y = 4000.0
@@ -341,7 +341,7 @@ def run_all_tests(robot_tester):
     return result
 
 
-def fwd_pose(x=0.0, y=0.0, z=0.01):
+def fwd_pose(x: float = 0.0, y: float = 0.0, z: float = 0.01) -> Pose:
     initial_pose = Pose()
     initial_pose.position.x = x
     initial_pose.position.y = y
@@ -353,7 +353,7 @@ def fwd_pose(x=0.0, y=0.0, z=0.01):
     return initial_pose
 
 
-def get_testers(args):
+def get_testers(args: argparse.Namespace) -> list[NavTester]:
     testers = []
 
     init_x, init_y, final_x, final_y = args.robot[0]
@@ -376,7 +376,7 @@ def get_testers(args):
     return testers
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     # The robot(s) positions from the input arguments
     parser = argparse.ArgumentParser(description='System-level navigation tester node')
     group = parser.add_mutually_exclusive_group(required=True)
diff --git a/nav2_system_tests/src/system/nav_through_poses_tester_node.py b/nav2_system_tests/src/system/nav_through_poses_tester_node.py
index 6109223c82a..02c793d5507 100755
--- a/nav2_system_tests/src/system/nav_through_poses_tester_node.py
+++ b/nav2_system_tests/src/system/nav_through_poses_tester_node.py
@@ -25,7 +25,7 @@
 from nav2_msgs.action import NavigateThroughPoses
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
 
@@ -55,16 +55,16 @@ def __init__(self, initial_pose: Pose, goal_pose: Pose, namespace: str = ''):
             self, NavigateThroughPoses, 'navigate_through_poses'
         )
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info('\033[1;37;44m' + msg + '\033[0m')
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn('\033[1;37;43m' + msg + '\033[0m')
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error('\033[1;37;41m' + msg + '\033[0m')
 
-    def setInitialPose(self):
+    def setInitialPose(self) -> None:
         msg = PoseWithCovarianceStamped()
         msg.pose.pose = self.initial_pose
         msg.header.frame_id = 'map'
@@ -72,13 +72,13 @@ def setInitialPose(self):
         self.initial_pose_pub.publish(msg)
         self.currentPose = self.initial_pose
 
-    def getStampedPoseMsg(self, pose: Pose):
+    def getStampedPoseMsg(self, pose: Pose) -> PoseStamped:
         msg = PoseStamped()
         msg.header.frame_id = 'map'
         msg.pose = pose
         return msg
 
-    def runNavigateAction(self, goal_pose: Optional[Pose] = None):
+    def runNavigateAction(self, goal_pose: Optional[Pose] = None) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateThroughPoses' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -101,7 +101,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -110,9 +110,9 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
-            result = get_result_future.result().result
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.info_msg(f'Goal failed with status code: {status}'
                           f' error code:{result.error_code}'
                           f' error msg:{result.error_msg}')
@@ -121,7 +121,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         self.info_msg('Goal succeeded!')
         return True
 
-    def runFakeNavigateAction(self):
+    def runFakeNavigateAction(self) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateThroughPoses' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -137,7 +137,7 @@ def runFakeNavigateAction(self):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -146,9 +146,9 @@ def runFakeNavigateAction(self):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
-            result = get_result_future.result().result
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.info_msg(f'Goal failed with status code: {status}'
                           f' error code:{result.error_code}'
                           f' error msg:{result.error_msg}')
@@ -157,7 +157,7 @@ def runFakeNavigateAction(self):
         self.info_msg('Goal succeeded!')
         return True
 
-    def runNavigatePreemptionAction(self, block):
+    def runNavigatePreemptionAction(self, block: bool) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateThroughPoses' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -174,7 +174,7 @@ def runNavigatePreemptionAction(self, block):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -186,9 +186,9 @@ def runNavigatePreemptionAction(self, block):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
-            result = get_result_future.result().result
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.info_msg(f'Goal failed with status code: {status}'
                           f' error code:{result.error_code}'
                           f' error msg:{result.error_msg}')
@@ -197,12 +197,12 @@ def runNavigatePreemptionAction(self, block):
         self.info_msg('Goal succeeded!')
         return True
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.current_pose = msg.pose.pose
         self.initial_pose_received = True
 
-    def wait_for_node_active(self, node_name: str):
+    def wait_for_node_active(self, node_name: str) -> None:
         # Waits for the node within the tester namespace to become active
         self.info_msg(f'Waiting for {node_name} to become active')
         node_service = f'{node_name}/get_state'
@@ -216,7 +216,7 @@ def wait_for_node_active(self, node_name: str):
             future = state_client.call_async(req)
             rclpy.spin_until_future_complete(self, future)
             if future.result() is not None:
-                state = future.result().current_state.label
+                state = future.result().current_state.label  # type: ignore[union-attr]
                 self.info_msg(f'Result of get_state: {state}')
             else:
                 self.error_msg(
@@ -224,7 +224,7 @@ def wait_for_node_active(self, node_name: str):
                 )
             time.sleep(5)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
         self.action_client.destroy()
 
@@ -259,7 +259,7 @@ def shutdown(self):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-    def wait_for_initial_pose(self):
+    def wait_for_initial_pose(self) -> None:
         self.initial_pose_received = False
         while not self.initial_pose_received:
             self.info_msg('Setting initial pose')
@@ -268,7 +268,7 @@ def wait_for_initial_pose(self):
             rclpy.spin_once(self, timeout_sec=1)
 
 
-def run_all_tests(robot_tester):
+def run_all_tests(robot_tester: NavTester) -> bool:
     # set transforms to use_sim_time
     result = True
     if result:
@@ -292,7 +292,7 @@ def run_all_tests(robot_tester):
     return result
 
 
-def fwd_pose(x=0.0, y=0.0, z=0.01):
+def fwd_pose(x: float = 0.0, y: float = 0.0, z: float = 0.01) -> Pose:
     initial_pose = Pose()
     initial_pose.position.x = x
     initial_pose.position.y = y
@@ -304,7 +304,7 @@ def fwd_pose(x=0.0, y=0.0, z=0.01):
     return initial_pose
 
 
-def get_testers(args):
+def get_testers(args: argparse.Namespace) -> list[NavTester]:
     testers = []
 
     init_x, init_y, final_x, final_y = args.robot[0]
@@ -327,7 +327,7 @@ def get_testers(args):
     return testers
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     # The robot(s) positions from the input arguments
     parser = argparse.ArgumentParser(description='System-level navigation tester node')
     group = parser.add_mutually_exclusive_group(required=True)
diff --git a/nav2_system_tests/src/system/nav_to_pose_tester_node.py b/nav2_system_tests/src/system/nav_to_pose_tester_node.py
index 24a60bb0882..222d0f8237a 100755
--- a/nav2_system_tests/src/system/nav_to_pose_tester_node.py
+++ b/nav2_system_tests/src/system/nav_to_pose_tester_node.py
@@ -21,7 +21,7 @@
 import struct
 import sys
 import time
-from typing import Optional
+from typing import Any, Optional
 
 from action_msgs.msg import GoalStatus
 from geometry_msgs.msg import Pose, PoseStamped, PoseWithCovarianceStamped
@@ -29,7 +29,7 @@
 from nav2_msgs.action import NavigateToPose
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
 import zmq
@@ -60,16 +60,16 @@ def __init__(self, initial_pose: Pose, goal_pose: Pose, namespace: str = ''):
         self.set_initial_pose_timeout = 15
         self.action_client = ActionClient(self, NavigateToPose, 'navigate_to_pose')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info('\033[1;37;44m' + msg + '\033[0m')
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn('\033[1;37;43m' + msg + '\033[0m')
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error('\033[1;37;41m' + msg + '\033[0m')
 
-    def setInitialPose(self):
+    def setInitialPose(self) -> None:
         msg = PoseWithCovarianceStamped()
         msg.pose.pose = self.initial_pose
         msg.header.frame_id = 'map'
@@ -77,17 +77,17 @@ def setInitialPose(self):
         self.initial_pose_pub.publish(msg)
         self.currentPose = self.initial_pose
 
-    def getStampedPoseMsg(self, pose: Pose):
+    def getStampedPoseMsg(self, pose: Pose) -> PoseStamped:
         msg = PoseStamped()
         msg.header.frame_id = 'map'
         msg.pose = pose
         return msg
 
-    def publishGoalPose(self, goal_pose: Optional[Pose] = None):
+    def publishGoalPose(self, goal_pose: Optional[Pose] = None) -> None:
         self.goal_pose = goal_pose if goal_pose is not None else self.goal_pose
         self.goal_pub.publish(self.getStampedPoseMsg(self.goal_pose))
 
-    def runNavigateAction(self, goal_pose: Optional[Pose] = None):
+    def runNavigateAction(self, goal_pose: Optional[Pose] = None) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateToPose' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -109,7 +109,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -131,9 +131,9 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_SUCCEEDED:
-            result = get_result_future.result().result
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.info_msg(f'Goal failed with status code: {status}'
                           f' error code:{result.error_code}'
                           f' error msg:{result.error_msg}')
@@ -145,7 +145,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         self.info_msg('Goal succeeded!')
         return True
 
-    def grootMonitoringReloadTree(self):
+    def grootMonitoringReloadTree(self) -> bool:
         # ZeroMQ Context
         context = zmq.Context()
 
@@ -191,7 +191,7 @@ def grootMonitoringReloadTree(self):
 
         return True
 
-    def grootMonitoringSetBreakpoint(self):
+    def grootMonitoringSetBreakpoint(self) -> bool:
         # ZeroMQ Context
         context = zmq.Context()
         # Define the socket using the 'Context'
@@ -232,7 +232,7 @@ def grootMonitoringSetBreakpoint(self):
         self.info_msg('ZMQ - HOOK_INSERT request sent')
         return True
 
-    def grootMonitoringGetStatus(self):
+    def grootMonitoringGetStatus(self) -> bool:
         # ZeroMQ Context
         context = zmq.Context()
 
@@ -276,12 +276,12 @@ def grootMonitoringGetStatus(self):
         self.info_msg('ZMQ - Did receive status')
         return True
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.current_pose = msg.pose.pose
         self.initial_pose_received = True
 
-    def reachesGoal(self, timeout, distance):
+    def reachesGoal(self, timeout: float, distance: float) -> bool:
         goalReached = False
         start_time = time.time()
 
@@ -296,14 +296,17 @@ def reachesGoal(self, timeout, distance):
                     self.error_msg('Robot timed out reaching its goal!')
                     return False
 
-    def distanceFromGoal(self):
+        self.info_msg('Robot reached its goal!')
+        return True
+
+    def distanceFromGoal(self) -> float:
         d_x = self.current_pose.position.x - self.goal_pose.position.x
         d_y = self.current_pose.position.y - self.goal_pose.position.y
         distance = math.sqrt(d_x * d_x + d_y * d_y)
         self.info_msg(f'Distance from goal is: {distance}')
         return distance
 
-    def wait_for_node_active(self, node_name: str):
+    def wait_for_node_active(self, node_name: str) -> None:
         # Waits for the node within the tester namespace to become active
         self.info_msg(f'Waiting for {node_name} to become active')
         node_service = f'{node_name}/get_state'
@@ -317,7 +320,7 @@ def wait_for_node_active(self, node_name: str):
             future = state_client.call_async(req)
             rclpy.spin_until_future_complete(self, future)
             if future.result() is not None:
-                state = future.result().current_state.label
+                state = future.result().current_state.label  # type: ignore[union-attr]
                 self.info_msg(f'Result of get_state: {state}')
             else:
                 self.error_msg(
@@ -325,7 +328,7 @@ def wait_for_node_active(self, node_name: str):
                 )
             time.sleep(5)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
         self.action_client.destroy()
 
@@ -360,13 +363,13 @@ def shutdown(self):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-    def wait_for_initial_pose(self):
+    def wait_for_initial_pose(self) -> bool:
         self.initial_pose_received = False
         # If the initial pose is not received within 100 seconds, return False
         # this is because when setting a wrong initial pose, amcl_pose is not received
         # and the test will hang indefinitely
         start_time = time.time()
-        duration = 0
+        duration = 0.0
         while not self.initial_pose_received:
             self.info_msg('Setting initial pose')
             self.setInitialPose()
@@ -379,14 +382,14 @@ def wait_for_initial_pose(self):
         return True
 
 
-def test_RobotMovesToGoal(robot_tester):
+def test_RobotMovesToGoal(robot_tester: NavTester) -> bool:
     robot_tester.info_msg('Setting goal pose')
     robot_tester.publishGoalPose()
     robot_tester.info_msg('Waiting 60 seconds for robot to reach goal')
     return robot_tester.reachesGoal(timeout=60, distance=0.5)
 
 
-def run_all_tests(robot_tester):
+def run_all_tests(robot_tester: NavTester) -> bool:
     # set transforms to use_sim_time
     result = True
     if result:
@@ -409,7 +412,7 @@ def run_all_tests(robot_tester):
     return result
 
 
-def fwd_pose(x=0.0, y=0.0, z=0.01):
+def fwd_pose(x: float = 0.0, y: float = 0.0, z: float = 0.01) -> Pose:
     initial_pose = Pose()
     initial_pose.position.x = x
     initial_pose.position.y = y
@@ -421,7 +424,7 @@ def fwd_pose(x=0.0, y=0.0, z=0.01):
     return initial_pose
 
 
-def get_testers(args):
+def get_testers(args: argparse.Namespace) -> list[NavTester]:
     testers = []
 
     if args.robot:
@@ -469,7 +472,7 @@ def get_testers(args):
     return testers
 
 
-def check_args(expect_failure: str):
+def check_args(expect_failure: str) -> Any:
     # Check if --expect_failure is True or False
     if expect_failure != 'True' and expect_failure != 'False':
         print(
@@ -480,7 +483,7 @@ def check_args(expect_failure: str):
         return eval(expect_failure)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     # The robot(s) positions from the input arguments
     parser = argparse.ArgumentParser(description='System-level navigation tester node')
     parser.add_argument('-e', '--expect_failure')
diff --git a/nav2_system_tests/src/system/test_multi_robot_launch.py b/nav2_system_tests/src/system/test_multi_robot_launch.py
index ed8bdc00e3b..e39a6993f77 100755
--- a/nav2_system_tests/src/system/test_multi_robot_launch.py
+++ b/nav2_system_tests/src/system/test_multi_robot_launch.py
@@ -27,16 +27,16 @@
 from launch_testing.legacy import LaunchTestService
 
 
-def generate_launch_description():
-    map_yaml_file = os.getenv('TEST_MAP')
-    world = os.getenv('TEST_WORLD')
-    urdf = os.getenv('TEST_URDF')
-    sdf = os.getenv('TEST_SDF')
+def generate_launch_description() -> LaunchDescription:
+    map_yaml_file = os.getenv('TEST_MAP', '')
+    world = os.getenv('TEST_WORLD', '')
+    urdf = os.getenv('TEST_URDF', '')
+    sdf = os.getenv('TEST_SDF', '')
 
     bt_xml_file = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     bringup_dir = get_package_share_directory('nav2_bringup')
@@ -157,13 +157,13 @@ def generate_launch_description():
     return ld
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     # TODO(orduno) remove duplicated definition of robots on `generate_launch_description`
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), os.getenv('TESTER')),
+            os.path.join(os.getenv('TEST_DIR', ''), os.getenv('TESTER', '')),
             '-rs',
             'robot1',
             '0.0',
diff --git a/nav2_system_tests/src/system/test_system_launch.py b/nav2_system_tests/src/system/test_system_launch.py
index 7713d2815a1..e93efc9a646 100755
--- a/nav2_system_tests/src/system/test_system_launch.py
+++ b/nav2_system_tests/src/system/test_system_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -46,7 +46,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     # Use local param file
@@ -65,10 +65,10 @@ def generate_launch_description():
         param_substitutions.update({'enable_groot_monitoring': 'True'})
 
     param_substitutions.update(
-        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER')}
+        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER', '')}
     )
     param_substitutions.update(
-        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER')}
+        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER', '')}
     )
 
     configured_params = RewrittenYaml(
@@ -137,12 +137,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), os.getenv('TESTER')),
+            os.path.join(os.getenv('TEST_DIR', ''), os.getenv('TESTER', '')),
             '-r',
             '-2.0',
             '-0.5',
diff --git a/nav2_system_tests/src/system/test_system_with_obstacle_launch.py b/nav2_system_tests/src/system/test_system_with_obstacle_launch.py
index b6fb8104ec4..8413da01458 100755
--- a/nav2_system_tests/src/system/test_system_with_obstacle_launch.py
+++ b/nav2_system_tests/src/system/test_system_with_obstacle_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
     nav2_system_tests_dir = get_package_share_directory('nav2_system_tests')
@@ -47,7 +47,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     # Use local param file
@@ -63,10 +63,10 @@ def generate_launch_description():
         param_substitutions.update({'use_astar': 'True'})
 
     param_substitutions.update(
-        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER')}
+        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER', '')}
     )
     param_substitutions.update(
-        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER')}
+        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER', '')}
     )
 
     configured_params = RewrittenYaml(
@@ -147,12 +147,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), os.getenv('TESTER')),
+            os.path.join(os.getenv('TEST_DIR', ''), os.getenv('TESTER', '')),
             '-r',
             '-2.0',
             '-0.5',
diff --git a/nav2_system_tests/src/system/test_wrong_init_pose_launch.py b/nav2_system_tests/src/system/test_wrong_init_pose_launch.py
index 7a2af3355a8..81ae8bd483c 100755
--- a/nav2_system_tests/src/system/test_wrong_init_pose_launch.py
+++ b/nav2_system_tests/src/system/test_wrong_init_pose_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -46,7 +46,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     # Use local param file
@@ -65,10 +65,10 @@ def generate_launch_description():
         param_substitutions.update({'enable_groot_monitoring': 'True'})
 
     param_substitutions.update(
-        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER')}
+        {'planner_server.ros__parameters.GridBased.plugin': os.getenv('PLANNER', '')}
     )
     param_substitutions.update(
-        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER')}
+        {'controller_server.ros__parameters.FollowPath.plugin': os.getenv('CONTROLLER', '')}
     )
 
     configured_params = RewrittenYaml(
@@ -137,12 +137,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), os.getenv('TESTER')),
+            os.path.join(os.getenv('TEST_DIR', ''), os.getenv('TESTER', '')),
             '-r',
             '-200000.0',
             '-200000.0',
diff --git a/nav2_system_tests/src/system_failure/test_system_failure_launch.py b/nav2_system_tests/src/system_failure/test_system_failure_launch.py
index 3e7f918e174..8b8e2542c6d 100755
--- a/nav2_system_tests/src/system_failure/test_system_failure_launch.py
+++ b/nav2_system_tests/src/system_failure/test_system_failure_launch.py
@@ -30,7 +30,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -46,7 +46,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', ''),
     )
 
     params_file = os.path.join(nav2_bringup_dir, 'params', 'nav2_params.yaml')
@@ -122,12 +122,12 @@ def generate_launch_description():
     )
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
         cmd=[
-            os.path.join(os.getenv('TEST_DIR'), 'tester_node.py'),
+            os.path.join(os.getenv('TEST_DIR', ''), 'tester_node.py'),
             '-r',
             '-2.0',
             '-0.5',
diff --git a/nav2_system_tests/src/system_failure/tester_node.py b/nav2_system_tests/src/system_failure/tester_node.py
index 9f296ff0d46..615f24f27ec 100755
--- a/nav2_system_tests/src/system_failure/tester_node.py
+++ b/nav2_system_tests/src/system_failure/tester_node.py
@@ -26,7 +26,7 @@
 from nav2_msgs.action import NavigateToPose
 from nav2_msgs.srv import ManageLifecycleNodes
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
 from rclpy.node import Node
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
 
@@ -55,16 +55,16 @@ def __init__(self, initial_pose: Pose, goal_pose: Pose, namespace: str = ''):
         self.goal_pose = goal_pose
         self.action_client = ActionClient(self, NavigateToPose, 'navigate_to_pose')
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info('\033[1;37;44m' + msg + '\033[0m')
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn('\033[1;37;43m' + msg + '\033[0m')
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error('\033[1;37;41m' + msg + '\033[0m')
 
-    def setInitialPose(self):
+    def setInitialPose(self) -> None:
         msg = PoseWithCovarianceStamped()
         msg.pose.pose = self.initial_pose
         msg.header.frame_id = 'map'
@@ -72,17 +72,17 @@ def setInitialPose(self):
         self.initial_pose_pub.publish(msg)
         self.currentPose = self.initial_pose
 
-    def getStampedPoseMsg(self, pose: Pose):
+    def getStampedPoseMsg(self, pose: Pose) -> PoseStamped:
         msg = PoseStamped()
         msg.header.frame_id = 'map'
         msg.pose = pose
         return msg
 
-    def publishGoalPose(self, goal_pose: Optional[Pose] = None):
+    def publishGoalPose(self, goal_pose: Optional[Pose] = None) -> None:
         self.goal_pose = goal_pose if goal_pose is not None else self.goal_pose
         self.goal_pub.publish(self.getStampedPoseMsg(self.goal_pose))
 
-    def runNavigateAction(self, goal_pose: Optional[Pose] = None):
+    def runNavigateAction(self, goal_pose: Optional[Pose] = None) -> bool:
         # Sends a `NavToPose` action request and waits for completion
         self.info_msg("Waiting for 'NavigateToPose' action server")
         while not self.action_client.wait_for_server(timeout_sec=1.0):
@@ -98,7 +98,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         rclpy.spin_until_future_complete(self, send_goal_future)
         goal_handle = send_goal_future.result()
 
-        if not goal_handle.accepted:
+        if not goal_handle or not goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -107,7 +107,7 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
 
         self.info_msg("Waiting for 'NavigateToPose' action to complete")
         rclpy.spin_until_future_complete(self, get_result_future)
-        status = get_result_future.result().status
+        status = get_result_future.result().status  # type: ignore[union-attr]
         if status != GoalStatus.STATUS_ABORTED:
             self.info_msg(f'Goal failed with status code: {status}')
             return False
@@ -115,12 +115,12 @@ def runNavigateAction(self, goal_pose: Optional[Pose] = None):
         self.info_msg('Goal failed, as expected!')
         return True
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.current_pose = msg.pose.pose
         self.initial_pose_received = True
 
-    def reachesGoal(self, timeout, distance):
+    def reachesGoal(self, timeout: float, distance: float) -> bool:
         goalReached = False
         start_time = time.time()
 
@@ -135,14 +135,17 @@ def reachesGoal(self, timeout, distance):
                     self.error_msg('Robot timed out reaching its goal!')
                     return False
 
-    def distanceFromGoal(self):
+        self.info_msg('Robot reached its goal!')
+        return True
+
+    def distanceFromGoal(self) -> float:
         d_x = self.current_pose.position.x - self.goal_pose.position.x
         d_y = self.current_pose.position.y - self.goal_pose.position.y
         distance = math.sqrt(d_x * d_x + d_y * d_y)
         self.info_msg(f'Distance from goal is: {distance}')
         return distance
 
-    def wait_for_node_active(self, node_name: str):
+    def wait_for_node_active(self, node_name: str) -> None:
         # Waits for the node within the tester namespace to become active
         self.info_msg(f'Waiting for {node_name} to become active')
         node_service = f'{node_name}/get_state'
@@ -156,7 +159,7 @@ def wait_for_node_active(self, node_name: str):
             future = state_client.call_async(req)
             rclpy.spin_until_future_complete(self, future)
             if future.result() is not None:
-                state = future.result().current_state.label
+                state = future.result().current_state.label  # type: ignore[union-attr]
                 self.info_msg(f'Result of get_state: {state}')
             else:
                 self.error_msg(
@@ -164,7 +167,7 @@ def wait_for_node_active(self, node_name: str):
                 )
             time.sleep(5)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
         self.action_client.destroy()
 
@@ -199,7 +202,7 @@ def shutdown(self):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-    def wait_for_initial_pose(self):
+    def wait_for_initial_pose(self) -> None:
         self.initial_pose_received = False
         while not self.initial_pose_received:
             self.info_msg('Setting initial pose')
@@ -208,7 +211,7 @@ def wait_for_initial_pose(self):
             rclpy.spin_once(self, timeout_sec=1)
 
 
-def run_all_tests(robot_tester):
+def run_all_tests(robot_tester: NavTester) -> bool:
     # set transforms to use_sim_time
     result = True
     if result:
@@ -227,7 +230,7 @@ def run_all_tests(robot_tester):
     return result
 
 
-def fwd_pose(x=0.0, y=0.0, z=0.01):
+def fwd_pose(x: float = 0.0, y: float = 0.0, z: float = 0.01) -> Pose:
     initial_pose = Pose()
     initial_pose.position.x = x
     initial_pose.position.y = y
@@ -239,7 +242,7 @@ def fwd_pose(x=0.0, y=0.0, z=0.01):
     return initial_pose
 
 
-def get_testers(args):
+def get_testers(args: argparse.Namespace) -> list[NavTester]:
     testers = []
 
     if args.robot:
@@ -266,7 +269,7 @@ def get_testers(args):
     return testers
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     # The robot(s) positions from the input arguments
     parser = argparse.ArgumentParser(description='System-level navigation tester node')
     group = parser.add_mutually_exclusive_group(required=True)
diff --git a/nav2_system_tests/src/updown/test_updown_launch.py b/nav2_system_tests/src/updown/test_updown_launch.py
index 8a70be4e727..e9312e3ae8b 100755
--- a/nav2_system_tests/src/updown/test_updown_launch.py
+++ b/nav2_system_tests/src/updown/test_updown_launch.py
@@ -20,7 +20,7 @@
 from launch_ros.actions import Node
 
 
-def generate_launch_description():
+def generate_launch_description() -> launch.LaunchDescription:
 
     # Configuration parameters for the launch
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
diff --git a/nav2_system_tests/src/updown/updownresults.py b/nav2_system_tests/src/updown/updownresults.py
index de38c51c8bf..1106267179f 100755
--- a/nav2_system_tests/src/updown/updownresults.py
+++ b/nav2_system_tests/src/updown/updownresults.py
@@ -28,7 +28,7 @@
 import sys
 
 
-def main():
+def main() -> None:
     log = sys.stdin
     test_count = 0
     fail_count = 0
diff --git a/nav2_system_tests/src/waypoint_follower/test_case_launch.py b/nav2_system_tests/src/waypoint_follower/test_case_launch.py
index eb581b373ad..0c92849d806 100755
--- a/nav2_system_tests/src/waypoint_follower/test_case_launch.py
+++ b/nav2_system_tests/src/waypoint_follower/test_case_launch.py
@@ -28,7 +28,7 @@
 from nav2_common.launch import RewrittenYaml
 
 
-def generate_launch_description():
+def generate_launch_description() -> LaunchDescription:
     sim_dir = get_package_share_directory('nav2_minimal_tb3_sim')
     nav2_bringup_dir = get_package_share_directory('nav2_bringup')
 
@@ -44,7 +44,7 @@ def generate_launch_description():
     bt_navigator_xml = os.path.join(
         get_package_share_directory('nav2_bt_navigator'),
         'behavior_trees',
-        os.getenv('BT_NAVIGATOR_XML'),
+        os.getenv('BT_NAVIGATOR_XML', '')
     )
 
     params_file = os.path.join(nav2_bringup_dir, 'params/nav2_params.yaml')
@@ -112,11 +112,11 @@ def generate_launch_description():
     ])
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     ld = generate_launch_description()
 
     test1_action = ExecuteProcess(
-        cmd=[os.path.join(os.getenv('TEST_DIR'), 'tester.py')],
+        cmd=[os.path.join(os.getenv('TEST_DIR', ''), 'tester.py')],
         name='tester_node',
         output='screen')
 
diff --git a/nav2_system_tests/src/waypoint_follower/tester.py b/nav2_system_tests/src/waypoint_follower/tester.py
index 87c7b332c94..c70198c5e8f 100755
--- a/nav2_system_tests/src/waypoint_follower/tester.py
+++ b/nav2_system_tests/src/waypoint_follower/tester.py
@@ -15,6 +15,7 @@
 
 import sys
 import time
+from typing import Optional
 
 from action_msgs.msg import GoalStatus
 from geometry_msgs.msg import PoseStamped, PoseWithCovarianceStamped
@@ -22,7 +23,8 @@
 from nav2_msgs.srv import ManageLifecycleNodes
 from rcl_interfaces.srv import SetParameters
 import rclpy
-from rclpy.action import ActionClient
+from rclpy.action import ActionClient  # type: ignore[attr-defined]
+from rclpy.action.client import ClientGoalHandle
 from rclpy.node import Node
 from rclpy.parameter import Parameter
 from rclpy.qos import QoSDurabilityPolicy, QoSHistoryPolicy, QoSProfile, QoSReliabilityPolicy
@@ -30,16 +32,18 @@
 
 class WaypointFollowerTest(Node):
 
-    def __init__(self):
+    def __init__(self) -> None:
         super().__init__(node_name='nav2_waypoint_tester', namespace='')
-        self.waypoints = None
+        self.waypoints: list[float] = []
         self.action_client = ActionClient(self, FollowWaypoints, 'follow_waypoints')
         self.initial_pose_pub = self.create_publisher(
             PoseWithCovarianceStamped, 'initialpose', 10
         )
         self.initial_pose_received = False
-        self.goal_handle = None
-        self.action_result = None
+        self.goal_handle: Optional[ClientGoalHandle[
+                FollowWaypoints.Goal, FollowWaypoints.Result,
+                FollowWaypoints.Feedback]] = None
+        self.action_result = FollowWaypoints.Result()
 
         pose_qos = QoSProfile(
             durability=QoSDurabilityPolicy.TRANSIENT_LOCAL,
@@ -55,7 +59,7 @@ def __init__(self):
             SetParameters, '/waypoint_follower/set_parameters'
         )
 
-    def setInitialPose(self, pose):
+    def setInitialPose(self, pose: list[float]) -> None:
         self.init_pose = PoseWithCovarianceStamped()
         self.init_pose.pose.pose.position.x = pose[0]
         self.init_pose.pose.pose.position.y = pose[1]
@@ -63,11 +67,11 @@ def setInitialPose(self, pose):
         self.publishInitialPose()
         time.sleep(5)
 
-    def poseCallback(self, msg):
+    def poseCallback(self, msg: PoseWithCovarianceStamped) -> None:
         self.info_msg('Received amcl_pose')
         self.initial_pose_received = True
 
-    def setWaypoints(self, waypoints):
+    def setWaypoints(self, waypoints: list[list[float]]) -> None:
         self.waypoints = []
         for wp in waypoints:
             msg = PoseStamped()
@@ -77,7 +81,7 @@ def setWaypoints(self, waypoints):
             msg.pose.orientation.w = 1.0
             self.waypoints.append(msg)
 
-    def run(self, block, cancel):
+    def run(self, block: bool, cancel: bool) -> bool:
         # if not self.waypoints:
         #     rclpy.error_msg('Did not set valid waypoints before running test!')
         #     return False
@@ -96,7 +100,7 @@ def run(self, block, cancel):
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
 
-        if not self.goal_handle.accepted:
+        if not self.goal_handle or not self.goal_handle.accepted:
             self.error_msg('Goal rejected')
             return False
 
@@ -112,8 +116,8 @@ def run(self, block, cancel):
         self.info_msg("Waiting for 'follow_waypoints' action to complete")
         try:
             rclpy.spin_until_future_complete(self, get_result_future)
-            status = get_result_future.result().status
-            result = get_result_future.result().result
+            status = get_result_future.result().status  # type: ignore[union-attr]
+            result = get_result_future.result().result  # type: ignore[union-attr]
             self.action_result = result
         except Exception as e:  # noqa: B902
             self.error_msg(f'Service call failed {e!r}')
@@ -124,17 +128,17 @@ def run(self, block, cancel):
         if len(self.action_result.missed_waypoints) > 0:
             self.info_msg(
                 'Goal failed to process all waypoints,'
-                ' missed {0} wps.'.format(len(self.action_result.missed_waypoints))
+                f' missed {len(self.action_result.missed_waypoints)} wps.'
             )
             return False
 
         self.info_msg('Goal succeeded!')
         return True
 
-    def publishInitialPose(self):
+    def publishInitialPose(self) -> None:
         self.initial_pose_pub.publish(self.init_pose)
 
-    def setStopFailureParam(self, value):
+    def setStopFailureParam(self, value: bool) -> None:
         req = SetParameters.Request()
         req.parameters = [
             Parameter('stop_on_failure', Parameter.Type.BOOL, value).to_parameter_msg()
@@ -142,7 +146,7 @@ def setStopFailureParam(self, value):
         future = self.param_cli.call_async(req)
         rclpy.spin_until_future_complete(self, future)
 
-    def shutdown(self):
+    def shutdown(self) -> None:
         self.info_msg('Shutting down')
 
         self.action_client.destroy()
@@ -180,21 +184,21 @@ def shutdown(self):
 
         self.info_msg(f'{transition_service} finished')
 
-    def cancel_goal(self):
-        cancel_future = self.goal_handle.cancel_goal_async()
+    def cancel_goal(self) -> None:
+        cancel_future = self.goal_handle.cancel_goal_async()  # type: ignore[union-attr]
         rclpy.spin_until_future_complete(self, cancel_future)
 
-    def info_msg(self, msg: str):
+    def info_msg(self, msg: str) -> None:
         self.get_logger().info(msg)
 
-    def warn_msg(self, msg: str):
+    def warn_msg(self, msg: str) -> None:
         self.get_logger().warn(msg)
 
-    def error_msg(self, msg: str):
+    def error_msg(self, msg: str) -> None:
         self.get_logger().error(msg)
 
 
-def main(argv=sys.argv[1:]):
+def main(argv: list[str] = sys.argv[1:]):  # type: ignore[no-untyped-def]
     rclpy.init()
 
     # wait a few seconds to make sure entire stacks are up
diff --git a/tools/pyproject.toml b/tools/pyproject.toml
index 938eef79689..86d0a1e414d 100644
--- a/tools/pyproject.toml
+++ b/tools/pyproject.toml
@@ -40,6 +40,9 @@ module = [
     "builtin_interfaces.*",
     "lifecycle_msgs.*",
     "geographic_msgs.*",
+    "rcl_interfaces.*",
+    "std_msgs.*",
+    "zmq.*",
 ]
 
 ignore_missing_imports = true