diff --git a/.release-please-individual-manifest.json b/.release-please-individual-manifest.json
index 475a5dbad8cd..f0c6cc21c435 100644
--- a/.release-please-individual-manifest.json
+++ b/.release-please-individual-manifest.json
@@ -1,5 +1,5 @@
 {
-  "packages/google-auth": "2.59.0",
+  "packages/google-auth": "2.59.1",
   "packages/google-cloud-apptopology": "0.1.0",
   "packages/google-cloud-ftp": "0.1.0",
   "packages/google-cloud-spanner": "3.71.0",
diff --git a/librarian.yaml b/librarian.yaml
index b2d08fc507d8..3d03c3deeb03 100644
--- a/librarian.yaml
+++ b/librarian.yaml
@@ -245,7 +245,7 @@ libraries:
       metadata_name_override: area120tables
       default_version: v1alpha1
   - name: google-auth
-    version: 2.59.0
+    version: 2.59.1
     python:
       library_type: AUTH
   - name: google-auth-httplib2
diff --git a/packages/google-auth/CHANGELOG.md b/packages/google-auth/CHANGELOG.md
index e233dca34dcc..1f51b3607fa8 100644
--- a/packages/google-auth/CHANGELOG.md
+++ b/packages/google-auth/CHANGELOG.md
@@ -4,6 +4,13 @@
 
 [1]: https://pypi.org/project/google-auth/#history
 
+## [2.59.1](https://github.com/googleapis/google-cloud-python/compare/google-auth-v2.59.0...google-auth-v2.59.1) (2026-09-30)
+
+
+### Bug Fixes
+
+* **auth:** support mTLS in requests.Request for token refresh and impersonation ([#18486](https://github.com/googleapis/google-cloud-python/issues/18486)) ([590376d](https://github.com/googleapis/google-cloud-python/commit/590376df522bf5f89e0d23b956a85db61c4d48d7))
+
 ## [2.59.0](https://github.com/googleapis/google-cloud-python/compare/google-auth-v2.58.1...google-auth-v2.59.0) (2026-09-28)
 
 
diff --git a/packages/google-auth/google/auth/version.py b/packages/google-auth/google/auth/version.py
index bc18d16d952d..b613318b89f2 100644
--- a/packages/google-auth/google/auth/version.py
+++ b/packages/google-auth/google/auth/version.py
@@ -12,4 +12,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = "2.59.0"
+__version__ = "2.59.1"