diff --git a/noxfile.py b/noxfile.py
index 73a771386..36a04fee4 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -22,7 +22,6 @@ def tests(session):
     session.install(".")
     # modules for testing
     session.install(
-        "mock>=4.0.3",
         "pyfakefs>=3.5,<3.7",
         "coverage==6.5.0",
     )
@@ -48,7 +47,6 @@ def tests_minimum_dependency_versions(session):
     session.install(".")
     # modules for testing
     session.install(
-        "mock>=4.0.3",
         "pyfakefs>=3.5,<3.7",
         "coverage==6.5.0",
         # Google-published dependencies pinned to the
diff --git a/tests/client_test.py b/tests/client_test.py
index 52e81c220..95b005d9f 100644
--- a/tests/client_test.py
+++ b/tests/client_test.py
@@ -15,7 +15,7 @@
 
 from importlib import import_module
 from inspect import getmembers
-import mock
+from unittest import mock
 import os
 import pickle
 from pyfakefs.fake_filesystem_unittest import TestCase as FileTestCase
diff --git a/tests/config_test.py b/tests/config_test.py
index 1a685cce0..21dcdabb5 100644
--- a/tests/config_test.py
+++ b/tests/config_test.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 """Tests the configuration helper module."""
 
-import mock
+from unittest import mock
 import os
 import yaml
 from pyfakefs.fake_filesystem_unittest import TestCase as FileTestCase
diff --git a/tests/interceptors/exception_interceptor_test.py b/tests/interceptors/exception_interceptor_test.py
index 2dfd2bf56..5c1f52814 100644
--- a/tests/interceptors/exception_interceptor_test.py
+++ b/tests/interceptors/exception_interceptor_test.py
@@ -14,7 +14,7 @@
 """Tests for the Exception gRPC Interceptor."""
 
 import grpc
-import mock
+from unittest import mock
 from unittest import TestCase
 
 from google.protobuf.message import Message as ProtobufMessageType
diff --git a/tests/interceptors/interceptor_test.py b/tests/interceptors/interceptor_test.py
index 0dec2b3df..4f2abd954 100644
--- a/tests/interceptors/interceptor_test.py
+++ b/tests/interceptors/interceptor_test.py
@@ -15,7 +15,7 @@
 
 
 from importlib import import_module
-import mock
+from unittest import mock
 from unittest import TestCase
 
 import grpc
diff --git a/tests/interceptors/logging_interceptor_test.py b/tests/interceptors/logging_interceptor_test.py
index 961a7b0cc..2cf5e752e 100644
--- a/tests/interceptors/logging_interceptor_test.py
+++ b/tests/interceptors/logging_interceptor_test.py
@@ -17,11 +17,10 @@
 from importlib import import_module
 import json
 import logging
+from unittest import mock
 from unittest import TestCase
 from types import SimpleNamespace
 
-import mock
-
 from google.ads.googleads import client as Client
 from google.ads.googleads.interceptors import LoggingInterceptor
 from google.ads.googleads.interceptors.helpers import (
diff --git a/tests/interceptors/metadata_interceptor_test.py b/tests/interceptors/metadata_interceptor_test.py
index e927ff5b8..20c3fe89d 100644
--- a/tests/interceptors/metadata_interceptor_test.py
+++ b/tests/interceptors/metadata_interceptor_test.py
@@ -13,11 +13,10 @@
 # limitations under the License.
 """Tests for the Metadata gRPC Interceptor."""
 
+from unittest import mock
 from unittest import TestCase
 import sys
 
-import mock
-
 from google.ads.googleads.interceptors import MetadataInterceptor
 
 # Dynamically generate the current Python version as a string in the format
diff --git a/tests/oauth2_test.py b/tests/oauth2_test.py
index 416e8f5bf..95f3d23bb 100644
--- a/tests/oauth2_test.py
+++ b/tests/oauth2_test.py
@@ -13,7 +13,7 @@
 # limitations under the License.
 """Tests for the OAuth2 helper module."""
 
-import mock
+from unittest import mock
 from unittest import TestCase
 
 from google.ads.googleads import oauth2