diff --git a/cschwabpy/SchwabAsyncClient.py b/cschwabpy/SchwabAsyncClient.py
index f43b353..3e737d9 100644
--- a/cschwabpy/SchwabAsyncClient.py
+++ b/cschwabpy/SchwabAsyncClient.py
@@ -213,6 +213,23 @@ async def get_instruments_async(
             if not self.__keep_client_alive:
                 await client.aclose()
 
+    async def cancel_order_async(
+        self, account_number_hash: AccountNumberWithHashID, order_id: int
+    ) -> bool:
+        """Cancel an order by order ID."""
+        await self._ensure_valid_access_token()
+        target_url = f"{SCHWAB_TRADER_API_BASE_URL}/accounts/{account_number_hash.hashValue}/orders/{order_id}"
+        client = httpx.AsyncClient() if self.__client is None else self.__client
+        try:
+            response = await client.delete(
+                url=target_url, params={}, headers=self.__auth_header()
+            )
+
+            return response.status_code == 200
+        finally:
+            if not self.__keep_client_alive:
+                await client.aclose()
+
     async def place_order_async(
         self, account_number_hash: AccountNumberWithHashID, order: Order
     ) -> int:
diff --git a/cschwabpy/SchwabClient.py b/cschwabpy/SchwabClient.py
index e2762fb..4539dc5 100644
--- a/cschwabpy/SchwabClient.py
+++ b/cschwabpy/SchwabClient.py
@@ -215,6 +215,23 @@ def get_instruments(
             if not self.__keep_client_alive:
                 client.close()
 
+    def cancel_order(
+        self, account_number_hash: AccountNumberWithHashID, order_id: int
+    ) -> bool:
+        """Cancel an order by order ID."""
+        self._ensure_valid_access_token()
+        target_url = f"{SCHWAB_TRADER_API_BASE_URL}/accounts/{account_number_hash.hashValue}/orders/{order_id}"
+        client = httpx.Client() if self.__client is None else self.__client
+        try:
+            response = client.delete(
+                url=target_url, params={}, headers=self.__auth_header()
+            )
+
+            return response.status_code == 200
+        finally:
+            if not self.__keep_client_alive:
+                client.close()
+
     def place_order(
         self, account_number_hash: AccountNumberWithHashID, order: Order
     ) -> int:
diff --git a/tests/test_models.py b/tests/test_models.py
index 95d77c3..e6bca15 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -234,6 +234,44 @@ async def test_place_order(httpx_mock: HTTPXMock):
         assert new_order_id2 == order_id
 
 
+@pytest.mark.asyncio
+async def test_cancel_order(httpx_mock: HTTPXMock):
+    mocked_token = mock_tokens()
+    token_store = LocalTokenStore()
+    if os.path.exists(Path(token_store.token_output_path)):
+        os.remove(token_store.token_output_path)  # clean up before test
+
+    order_id = 1000847830245
+    token_store.save_tokens(mocked_token)
+    httpx_mock.add_response(status_code=200)
+    async with httpx.AsyncClient() as client:
+        cschwab_client = SchwabAsyncClient(
+            app_client_id="fake_id",
+            app_secret="fake_secret",
+            token_store=token_store,
+            tokens=mocked_token,
+            http_client=client,
+        )
+        is_canceled = await cschwab_client.cancel_order_async(
+            account_number_hash=mock_account(), order_id=order_id
+        )
+        assert is_canceled
+
+    with httpx.Client() as client2:
+        cschwab_client = SchwabClient(
+            app_client_id="fake_id",
+            app_secret="fake_secret",
+            token_store=token_store,
+            http_client=client2,
+        )
+
+        is_canceled2 = cschwab_client.cancel_order(
+            account_number_hash=mock_account(),
+            order_id=order_id,
+        )
+        assert is_canceled2
+
+
 @pytest.mark.asyncio
 async def test_get_order_by_id(httpx_mock: HTTPXMock):
     json_mock = get_mock_response()["filled_order"]