diff --git a/.github/workflows/tests.yaml b/.github/workflows/tests.yaml
index 9db56f8b0c..3e2d1436cb 100644
--- a/.github/workflows/tests.yaml
+++ b/.github/workflows/tests.yaml
@@ -18,14 +18,8 @@ env:
   PROTOC_VERSION: 3.20.2
   OLDEST_PYTHON: 3.7
   LATEST_STABLE_PYTHON: 3.14
-  # TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-  # Switch this to Python 3.15 alpha1 pre-release
-  # https://peps.python.org/pep-0790/
-  PREVIEW_PYTHON_VERSION: 3.14
-  # TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-  # Add Python 3.15 alpha1 pre-release
-  # https://peps.python.org/pep-0790/
-  ALL_PYTHON: "['3.7', '3.8', '3.9', '3.10', '3.11', '3.12', '3.13', '3.14']"
+  PREVIEW_PYTHON_VERSION: 3.15
+  ALL_PYTHON: "['3.7', '3.8', '3.9', '3.10', '3.11', '3.12', '3.13', '3.14', '3.15']"
 
 permissions:
   contents: read
diff --git a/gapic/ads-templates/noxfile.py.j2 b/gapic/ads-templates/noxfile.py.j2
index 48646feb5e..7747ce4447 100644
--- a/gapic/ads-templates/noxfile.py.j2
+++ b/gapic/ads-templates/noxfile.py.j2
@@ -7,9 +7,6 @@ import os
 import nox  # type: ignore
 
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Add tests for Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
 ALL_PYTHON = [
     "3.7",
     "3.8",
@@ -19,6 +16,7 @@ ALL_PYTHON = [
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 @nox.session(python=ALL_PYTHON)
diff --git a/gapic/templates/noxfile.py.j2 b/gapic/templates/noxfile.py.j2
index 976fa2ccad..44a5aa8561 100644
--- a/gapic/templates/noxfile.py.j2
+++ b/gapic/templates/noxfile.py.j2
@@ -30,14 +30,12 @@ ALL_PYTHON = [
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/noxfile.py b/noxfile.py
index bfc4fff8b4..9d418afd45 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -45,9 +45,10 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 )
 
-NEWEST_PYTHON = ALL_PYTHON[-1]
+NEWEST_PYTHON = "3.14"
 
 
 @nox.session(python=ALL_PYTHON)
diff --git a/tests/integration/goldens/asset/noxfile.py b/tests/integration/goldens/asset/noxfile.py
index 842750346c..09effbb26f 100755
--- a/tests/integration/goldens/asset/noxfile.py
+++ b/tests/integration/goldens/asset/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/credentials/noxfile.py b/tests/integration/goldens/credentials/noxfile.py
index e5f8864a33..4f72800734 100755
--- a/tests/integration/goldens/credentials/noxfile.py
+++ b/tests/integration/goldens/credentials/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/eventarc/noxfile.py b/tests/integration/goldens/eventarc/noxfile.py
index 9af468e682..5b294b78b6 100755
--- a/tests/integration/goldens/eventarc/noxfile.py
+++ b/tests/integration/goldens/eventarc/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/logging/noxfile.py b/tests/integration/goldens/logging/noxfile.py
index 0aa3b63010..cb4075234c 100755
--- a/tests/integration/goldens/logging/noxfile.py
+++ b/tests/integration/goldens/logging/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/logging_internal/noxfile.py b/tests/integration/goldens/logging_internal/noxfile.py
index 0aa3b63010..cb4075234c 100755
--- a/tests/integration/goldens/logging_internal/noxfile.py
+++ b/tests/integration/goldens/logging_internal/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/redis/noxfile.py b/tests/integration/goldens/redis/noxfile.py
index d52df038ca..b354de4d67 100755
--- a/tests/integration/goldens/redis/noxfile.py
+++ b/tests/integration/goldens/redis/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()
 
diff --git a/tests/integration/goldens/redis_selective/noxfile.py b/tests/integration/goldens/redis_selective/noxfile.py
index d52df038ca..b354de4d67 100755
--- a/tests/integration/goldens/redis_selective/noxfile.py
+++ b/tests/integration/goldens/redis_selective/noxfile.py
@@ -37,14 +37,12 @@
     "3.12",
     "3.13",
     "3.14",
+    "3.15",
 ]
 
 DEFAULT_PYTHON_VERSION = "3.14"
 
-# TODO(https://github.com/googleapis/gapic-generator-python/issues/2450):
-# Switch this to Python 3.15 alpha1
-# https://peps.python.org/pep-0790/
-PREVIEW_PYTHON_VERSION = "3.14"
+PREVIEW_PYTHON_VERSION = "3.15"
 
 CURRENT_DIRECTORY = pathlib.Path(__file__).parent.absolute()