diff --git a/docs/source/format/Columnar.rst b/docs/source/format/Columnar.rst
index 62bb922afdd..73a34e57873 100644
--- a/docs/source/format/Columnar.rst
+++ b/docs/source/format/Columnar.rst
@@ -765,6 +765,68 @@ application.
 We discuss dictionary encoding as it relates to serialization further
 below.
 
+.. _run-length-encoded-layout:
+
+Run-Length Encoded Layout
+-------------------------
+
+Run-Length is a data representation that represents data as sequences of the
+same value, called runs. Each run is represented as a value, and an integer
+describing how often this value is repeated.
+
+Any array can be run-length encoded. A run-length encoded array has no buffers
+by itself, but has two child arrays. The first one holds a signed integer
+called a "run end" for each run. The run ends array can hold either 16, 32, or
+64-bit integers. The actual values of each run are held
+the second child array.
+
+The values in the first child array represent the length of each run. They do
+not hold the length of the respective run directly, but the accumulated length
+of all runs from the first to the current one, i.e. the logical index where the
+current run ends. This allows relatively efficient random access from a logical
+index using binary search. The length of an individual run can be determined by
+subtracting two adjacent values.
+
+A run must have have a length of at least 1. This means the values in the
+run ends array all positive and in strictly ascending order. A run end cannot be
+null.
+
+As an example, you could have the following data: ::
+
+    type: Float32
+    [1.0, 1.0, 1.0, 1.0, null, null, 2.0]
+
+In Run-length-encoded form, this could appear as:
+
+::
+
+    * Length: 7, Null count: 2
+    * Children arrays:
+
+      * run ends (Int32):
+        * Length: 3, Null count: 0
+        * Validity bitmap buffer: Not required
+        * Values buffer
+
+          | Bytes 0-3   | Bytes 4-7   | Bytes 8-11  | Bytes  6-63           |
+          |-------------|-------------|-------------|-----------------------|
+          | 4           | 6           | 7           | unspecified (padding) |
+
+    * values (Float32):
+        * Length: 3, Null count: 1
+        * Validity bitmap buffer:
+
+          | Byte 0 (validity bitmap) | Bytes 1-63            |
+          |--------------------------|-----------------------|
+          | 00000101                 | 0 (padding)           |
+
+        * Values buffer
+
+          | Bytes 0-3   | Bytes 4-7   | Bytes 8-11  | Bytes  6-63           |
+          |-------------|-------------|-------------|-----------------------|
+          | 1.0         | unspecified | 2.0         | unspecified (padding) |
+
+
 Buffer Listing for Each Layout
 ------------------------------
 
@@ -784,6 +846,7 @@ of memory buffers for each layout.
    "Dense Union",type ids,offsets,
    "Null",,,
    "Dictionary-encoded",validity,data (indices),
+   "Run-length encoded",,,
 
 Logical Types
 =============