diff --git a/.github/workflows/gapic-generator-tests.yml b/.github/workflows/gapic-generator-tests.yml
index 17fb7c64f7fe..90b53dcf9c5e 100644
--- a/.github/workflows/gapic-generator-tests.yml
+++ b/.github/workflows/gapic-generator-tests.yml
@@ -154,10 +154,10 @@ jobs:
       - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
         with:
           persist-credentials: false
-      - name: Set up Python ${{ needs.python_config.outputs.prerelease_python }}
+      - name: Set up Python ${{ needs.python_config.outputs.latest_stable_python }}
         uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6
         with:
-          python-version: ${{ needs.python_config.outputs.prerelease_python }}
+          python-version: ${{ needs.python_config.outputs.latest_stable_python }}
           allow-prereleases: true
           # Caches compiled wheels locally to prevent building heavy libraries 
           # such as grpcio, which we build from scratch on every run for Python 3.15+.
diff --git a/packages/gapic-generator/gapic/templates/noxfile.py.j2 b/packages/gapic-generator/gapic/templates/noxfile.py.j2
index 8db595319396..93f7313c19ca 100644
--- a/packages/gapic-generator/gapic/templates/noxfile.py.j2
+++ b/packages/gapic-generator/gapic/templates/noxfile.py.j2
@@ -457,7 +457,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -572,7 +572,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/asset/noxfile.py b/packages/gapic-generator/tests/integration/goldens/asset/noxfile.py
index 09d28712c73c..1094ac0f97cb 100755
--- a/packages/gapic-generator/tests/integration/goldens/asset/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/asset/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/credentials/noxfile.py b/packages/gapic-generator/tests/integration/goldens/credentials/noxfile.py
index 65e26efe21d3..087722a1e6c0 100755
--- a/packages/gapic-generator/tests/integration/goldens/credentials/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/credentials/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/eventarc/noxfile.py b/packages/gapic-generator/tests/integration/goldens/eventarc/noxfile.py
index 42b2349e2cc1..23ac067bdef0 100755
--- a/packages/gapic-generator/tests/integration/goldens/eventarc/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/eventarc/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/logging/noxfile.py b/packages/gapic-generator/tests/integration/goldens/logging/noxfile.py
index 09e4b345592a..9f862041977f 100755
--- a/packages/gapic-generator/tests/integration/goldens/logging/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/logging/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/logging_internal/noxfile.py b/packages/gapic-generator/tests/integration/goldens/logging_internal/noxfile.py
index 09e4b345592a..9f862041977f 100755
--- a/packages/gapic-generator/tests/integration/goldens/logging_internal/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/logging_internal/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/redis/noxfile.py b/packages/gapic-generator/tests/integration/goldens/redis/noxfile.py
index 9b3356dd1272..a28f14fbec56 100755
--- a/packages/gapic-generator/tests/integration/goldens/redis/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/redis/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/redis_selective/noxfile.py b/packages/gapic-generator/tests/integration/goldens/redis_selective/noxfile.py
index 9b3356dd1272..a28f14fbec56 100755
--- a/packages/gapic-generator/tests/integration/goldens/redis_selective/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/redis_selective/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
diff --git a/packages/gapic-generator/tests/integration/goldens/storagebatchoperations/noxfile.py b/packages/gapic-generator/tests/integration/goldens/storagebatchoperations/noxfile.py
index db370dd3dd0f..3308db78f076 100755
--- a/packages/gapic-generator/tests/integration/goldens/storagebatchoperations/noxfile.py
+++ b/packages/gapic-generator/tests/integration/goldens/storagebatchoperations/noxfile.py
@@ -449,7 +449,7 @@ def docfx(session):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],
@@ -564,7 +564,7 @@ def prerelease_deps(session, protobuf_implementation):
     )
 
 
-@nox.session(python=PREVIEW_PYTHON_VERSION)
+@nox.session(python=DEFAULT_PYTHON_VERSION)
 @nox.parametrize(
     "protobuf_implementation",
     ["python", "upb"],