diff --git a/CHANGELOG.md b/CHANGELOG.md
index 13bbfcdb79..57fa44b8ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 * Drop support for Python 3.8
 
+### Added
+
+* Expose `FunctionAuth` from the public API. (#3699)
+
 ## 0.28.1 (6th December, 2024)
 
 * Fix SSL case where `verify=False` together with client side certificates.
diff --git a/httpx/__init__.py b/httpx/__init__.py
index e9addde071..63225040ba 100644
--- a/httpx/__init__.py
+++ b/httpx/__init__.py
@@ -50,6 +50,7 @@ def main() -> None:  # type: ignore
     "DecodingError",
     "delete",
     "DigestAuth",
+    "FunctionAuth",
     "get",
     "head",
     "Headers",
diff --git a/httpx/_auth.py b/httpx/_auth.py
index b03971ab4b..9d24faed99 100644
--- a/httpx/_auth.py
+++ b/httpx/_auth.py
@@ -16,7 +16,7 @@
     from hashlib import _Hash
 
 
-__all__ = ["Auth", "BasicAuth", "DigestAuth", "NetRCAuth"]
+__all__ = ["Auth", "BasicAuth", "DigestAuth", "FunctionAuth", "NetRCAuth"]
 
 
 class Auth: