diff --git a/api/BUILD.gn b/api/BUILD.gn
index 12511518f5..59eec12698 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -1143,6 +1143,16 @@ if (rtc_include_tests) {
     ]
   }
 
+  rtc_source_set("mock_session_description_interface") {
+    visibility = [ "*" ]
+    testonly = true
+    sources = [ "test/mock_session_description_interface.h" ]
+    deps = [
+      ":libjingle_peerconnection_api",
+      "../test:test_support",
+    ]
+  }
+
   rtc_source_set("mock_async_dns_resolver") {
     visibility = [ "*" ]
     testonly = true
@@ -1349,6 +1359,7 @@ if (rtc_include_tests) {
       ":mock_peer_connection_factory_interface",
       ":mock_peerconnectioninterface",
       ":mock_rtp",
+      ":mock_session_description_interface",
       ":mock_transformable_video_frame",
       ":mock_video_bitrate_allocator",
       ":mock_video_bitrate_allocator_factory",
diff --git a/api/test/mock_session_description_interface.h b/api/test/mock_session_description_interface.h
new file mode 100644
index 0000000000..2a6ce0c662
--- /dev/null
+++ b/api/test/mock_session_description_interface.h
@@ -0,0 +1,51 @@
+/*
+ *  Copyright 2022 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef API_TEST_MOCK_SESSION_DESCRIPTION_INTERFACE_H_
+#define API_TEST_MOCK_SESSION_DESCRIPTION_INTERFACE_H_
+
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "api/jsep.h"
+#include "test/gmock.h"
+
+namespace webrtc {
+
+class MockSessionDescriptionInterface : public SessionDescriptionInterface {
+ public:
+  MOCK_METHOD(std::unique_ptr<SessionDescriptionInterface>,
+              Clone,
+              (),
+              (const, override));
+  MOCK_METHOD(cricket::SessionDescription*, description, (), (override));
+  MOCK_METHOD(const cricket::SessionDescription*,
+              description,
+              (),
+              (const, override));
+  MOCK_METHOD(SdpType, GetType, (), (const, override));
+  MOCK_METHOD(std::string, type, (), (const, override));
+  MOCK_METHOD(bool, AddCandidate, (const IceCandidateInterface*), (override));
+  MOCK_METHOD(size_t,
+              RemoveCandidates,
+              (const std::vector<cricket::Candidate>&),
+              (override));
+  MOCK_METHOD(size_t, number_of_mediasections, (), (const, override));
+  MOCK_METHOD(IceCandidateCollection*, candidates, (size_t), (const, override));
+  MOCK_METHOD(bool, ToString, (std::string*), (const, override));
+};
+
+static_assert(!std::is_abstract_v<MockSessionDescriptionInterface>);
+
+}  // namespace webrtc
+
+#endif  // API_TEST_MOCK_SESSION_DESCRIPTION_INTERFACE_H_