diff --git a/ci/builders/linux_android_debug_engine.json b/ci/builders/linux_android_debug_engine.json
index e004a47b6822f..07be90ab6c690 100644
--- a/ci/builders/linux_android_debug_engine.json
+++ b/ci/builders/linux_android_debug_engine.json
@@ -33,7 +33,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for android_jit_release_x86",
                     "parameters": [
                         "--variant",
@@ -115,7 +115,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for android_debug",
                     "parameters": [
                         "--variant",
diff --git a/ci/builders/linux_host_engine.json b/ci/builders/linux_host_engine.json
index 876fca52c101c..395b5ec9270ad 100644
--- a/ci/builders/linux_host_engine.json
+++ b/ci/builders/linux_host_engine.json
@@ -53,7 +53,7 @@
           },
           "tests": [
             {
-                "language": "python",
+                "language": "python3",
                 "name": "Host Tests for host_debug_impeller_vulkan",
                 "parameters": [
                     "--variant",
@@ -148,7 +148,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for host_profile",
                     "parameters": [
                         "--variant",
@@ -198,7 +198,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for host_release",
                     "parameters": [
                         "--variant",
diff --git a/ci/builders/mac_host_engine.json b/ci/builders/mac_host_engine.json
index 834563eeb142a..729ebf13f7c61 100644
--- a/ci/builders/mac_host_engine.json
+++ b/ci/builders/mac_host_engine.json
@@ -82,7 +82,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for host_profile",
                     "parameters": [
                         "--variant",
diff --git a/ci/builders/mac_ios_engine.json b/ci/builders/mac_ios_engine.json
index 68fc73f63ba68..9ae1f41b812bb 100644
--- a/ci/builders/mac_ios_engine.json
+++ b/ci/builders/mac_ios_engine.json
@@ -87,7 +87,7 @@
                     "out/ios_debug_sim_arm64"
                 ],
                 "script": "flutter/sky/tools/create_full_ios_framework.py",
-                "language": "python"
+                "language": "python3"
             },
             {
                 "name": "obj-c-doc",
diff --git a/ci/builders/mac_ios_engine_profile.json b/ci/builders/mac_ios_engine_profile.json
index ee762339ded0b..2d9891355a021 100644
--- a/ci/builders/mac_ios_engine_profile.json
+++ b/ci/builders/mac_ios_engine_profile.json
@@ -83,7 +83,7 @@
                     "out/ios_debug_sim_arm64"
                 ],
                 "script": "flutter/sky/tools/create_full_ios_framework.py",
-                "language": "python"
+                "language": "python3"
             }
         ]
     },
diff --git a/ci/builders/mac_ios_engine_release.json b/ci/builders/mac_ios_engine_release.json
index 269dd67d0e8cb..2de17631cf171 100644
--- a/ci/builders/mac_ios_engine_release.json
+++ b/ci/builders/mac_ios_engine_release.json
@@ -85,7 +85,7 @@
                     "--strip"
                 ],
                 "script": "flutter/sky/tools/create_full_ios_framework.py",
-                "language": "python"
+                "language": "python3"
             },
             {
                 "name": "release-nobitcode-FlutterMacOS.framework",
@@ -102,7 +102,7 @@
                     "--strip"
                 ],
                 "script": "flutter/sky/tools/create_full_ios_framework.py",
-                "language": "python"
+                "language": "python3"
             },
             {
                 "name": "Release-macos-gen-snapshots",
@@ -113,7 +113,7 @@
                     "out/ios_release"
                 ],
                 "script": "flutter/sky/tools/create_macos_gen_snapshots.py",
-                "language": "python"
+                "language": "python3"
             }
         ]
     },
diff --git a/ci/builders/windows_host_engine.json b/ci/builders/windows_host_engine.json
index a22943aae63db..3ca9c796c4fce 100644
--- a/ci/builders/windows_host_engine.json
+++ b/ci/builders/windows_host_engine.json
@@ -46,7 +46,7 @@
             },
             "tests": [
                 {
-                    "language": "python",
+                    "language": "python3",
                     "name": "Host Tests for host_debug",
                     "parameters": [
                         "--variant",
diff --git a/ci/compatibility_helper.py b/ci/compatibility_helper.py
new file mode 100644
index 0000000000000..0d8231ca178e7
--- /dev/null
+++ b/ci/compatibility_helper.py
@@ -0,0 +1,25 @@
+#!/usr/bin/env python3
+#
+# Copyright 2013 The Flutter Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+#
+# This script contains helper function(s) for supporting both
+# python 2 and python 3 infrastructure code.
+
+ENCODING = 'UTF-8'
+
+
+def byte_str_decode(str_or_bytes):
+  """Returns a string if given either a string or bytes.
+
+    TODO: This function should be removed when the supported python
+    version is only python 3.
+
+    Args:
+        str_or_bytes (string or bytes) we want to convert or return as
+        the possible value changes depending on the version of python
+        used.
+    """
+  return str_or_bytes if isinstance(str_or_bytes,
+                                    str) else str_or_bytes.decode(ENCODING)
diff --git a/ci/firebase_testlab.py b/ci/firebase_testlab.py
index 92069a7c1f584..510f582e8b82d 100755
--- a/ci/firebase_testlab.py
+++ b/ci/firebase_testlab.py
@@ -10,6 +10,7 @@
 import os
 import subprocess
 import sys
+from compatibility_helper import byte_str_decode
 
 if 'STORAGE_BUCKET' not in os.environ:
   print('The GCP storage bucket must be provided as an environment variable.')
@@ -67,6 +68,7 @@ def check_logcat(results_dir):
       'gsutil', 'cat',
       '%s/%s/*/logcat' % (BUCKET, results_dir)
   ])
+  logcat = byte_str_decode(logcat)
   if not logcat:
     sys.exit(1)
 
@@ -82,7 +84,9 @@ def check_timeline(results_dir):
       'gsutil', 'du',
       '%s/%s/*/game_loop_results/results_scenario_0.json' %
       (BUCKET, results_dir)
-  ]).strip()
+  ])
+  gsutil_du = byte_str_decode(gsutil_du)
+  gsutil_du = gsutil_du.strip()
   if gsutil_du == '0':
     print('Failed to produce a timeline.')
     sys.exit(1)
@@ -113,8 +117,9 @@ def main():
     return 1
 
   git_revision = subprocess.check_output(['git', 'rev-parse', 'HEAD'],
-                                         cwd=script_dir).strip()
-
+                                         cwd=script_dir)
+  git_revision = byte_str_decode(git_revision)
+  git_revision = git_revision.strip()
   results = []
   apk = None
   for apk in apks:
diff --git a/ci/scan_flattened_deps.py b/ci/scan_flattened_deps.py
index ece1154fb97a4..0184db7a9e6bf 100644
--- a/ci/scan_flattened_deps.py
+++ b/ci/scan_flattened_deps.py
@@ -17,6 +17,7 @@
 import subprocess
 import sys
 from urllib import request
+from compatibility_helper import byte_str_decode
 
 SCRIPT_DIR = os.path.dirname(sys.argv[0])
 CHECKOUT_ROOT = os.path.realpath(os.path.join(SCRIPT_DIR, '..'))
@@ -206,7 +207,9 @@ def get_common_ancestor_commit(dep, deps_list):
         'git --git-dir ' + temp_dep_dir + '/.git remote show upstream ' +
         "| sed -n \'/HEAD branch/s/.*: //p\'",
         shell=True
-    ).decode().strip()
+    )
+    default_branch = byte_str_decode(default_branch)
+    default_branch = default_branch.strip()
     print(
         'default_branch found: {default_branch}'.format(
             default_branch=default_branch
@@ -223,7 +226,8 @@ def get_common_ancestor_commit(dep, deps_list):
         "--format=\'%(objectname:short)\' refs/heads/upstream",
         shell=True
     )
-    commit = commit.decode().strip()
+    commit = byte_str_decode(commit)
+    commit = commit.strip()
 
     # perform merge-base on most recent default branch commit and pinned mirror commit
     ancestor_commit = subprocess.check_output(
@@ -232,7 +236,8 @@ def get_common_ancestor_commit(dep, deps_list):
         ),
         shell=True
     )
-    ancestor_commit = ancestor_commit.decode().strip()
+    ancestor_commit = byte_str_decode(ancestor_commit)
+    ancestor_commit = ancestor_commit.strip()
     print('Ancestor commit: ' + ancestor_commit)
     return ancestor_commit
   except subprocess.CalledProcessError as error:
diff --git a/testing/run_tests.py b/testing/run_tests.py
index acbfa9c0cac61..32b77d5397b04 100755
--- a/testing/run_tests.py
+++ b/testing/run_tests.py
@@ -32,7 +32,8 @@
 roboto_font_path = os.path.join(fonts_dir, 'Roboto-Regular.ttf')
 font_subset_dir = os.path.join(buildroot_dir, 'flutter', 'tools', 'font-subset')
 
-fml_unittests_filter = '--gtest_filter=-*TimeSensitiveTest*'
+FML_UNITTESTS_FILTER = '--gtest_filter=-*TimeSensitiveTest*'
+ENCODING = 'UTF-8'
 
 
 def PrintDivider(char='='):
@@ -341,7 +342,7 @@ def make_test(name, flags=repeat_flags, extra_env={}):
       make_test('embedder_a11y_unittests'),
       make_test('embedder_proctable_unittests'),
       make_test('embedder_unittests'),
-      make_test('fml_unittests', flags=[fml_unittests_filter] + repeat_flags),
+      make_test('fml_unittests', flags=[FML_UNITTESTS_FILTER] + repeat_flags),
       make_test('no_dart_plugin_registrant_unittests'),
       make_test('runtime_unittests'),
       make_test('testing_unittests'),
@@ -569,8 +570,13 @@ def EnsureIosTestsAreBuilt(ios_out_dir):
 def AssertExpectedXcodeVersion():
   """Checks that the user has a version of Xcode installed"""
   version_output = subprocess.check_output(['xcodebuild', '-version'])
-  match = re.match(b"Xcode (\d+)", version_output)
-  message = "Xcode must be installed to run the iOS embedding unit tests"
+  # TODO ricardoamador: remove this check when python 2 is deprecated.
+  version_output = version_output if isinstance(
+      version_output, str
+  ) else version_output.decode(ENCODING)
+  version_output = version_output.strip()
+  match = re.match(r'Xcode (\d+)', version_output)
+  message = 'Xcode must be installed to run the iOS embedding unit tests'
   assert match, message
 
 
diff --git a/tools/fuchsia/merge_and_upload_debug_symbols.py b/tools/fuchsia/merge_and_upload_debug_symbols.py
index 6e1038ed7ce1f..6005b6dcfc8ae 100755
--- a/tools/fuchsia/merge_and_upload_debug_symbols.py
+++ b/tools/fuchsia/merge_and_upload_debug_symbols.py
@@ -64,6 +64,7 @@ def CheckCIPDPackageExists(package_name, tag):
       tag,
   ]
   stdout = subprocess.check_output(command)
+  stdout = stdout if isinstance(stdout, str) else stdout.decode('UTF-8')
   match = re.search(r'No matching instances\.', stdout)
   if match:
     return False