diff --git a/changelog/10690.doc.rst b/changelog/10690.doc.rst
new file mode 100644
index 0000000000..faf61b3cc4
--- /dev/null
+++ b/changelog/10690.doc.rst
@@ -0,0 +1 @@
+Added `CI` and `BUILD_NUMBER` environment variables to the documentation.
diff --git a/doc/en/reference/reference.rst b/doc/en/reference/reference.rst
index b7bd4d1199..bbad27e09c 100644
--- a/doc/en/reference/reference.rst
+++ b/doc/en/reference/reference.rst
@@ -1047,6 +1047,14 @@ Environment Variables
 
 Environment variables that can be used to change pytest's behavior.
 
+.. envvar:: CI
+
+When set (regardless of value), pytest acknowledges that is running in a CI process. Alterative to ``BUILD_NUMBER`` variable.
+
+.. envvar:: BUILD_NUMBER
+
+When set (regardless of value), pytest acknowledges that is running in a CI process. Alterative to CI variable.
+
 .. envvar:: PYTEST_ADDOPTS
 
 This contains a command-line (parsed by the py:mod:`shlex` module) that will be **prepended** to the command line given