diff --git a/changelog/10690.doc.rst b/changelog/10690.doc.rst
new file mode 100644
index 000000000..f68fc2036
--- /dev/null
+++ b/changelog/10690.doc.rst
@@ -0,0 +1 @@
+Add CI and BUILD_NUMBER environment variables in documentation
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diff --git a/doc/en/reference/reference.rst b/doc/en/reference/reference.rst
index 288a4050d..c766a77b7 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