diff --git a/samcli/local/apigw/local_apigw_service.py b/samcli/local/apigw/local_apigw_service.py
index 088f34b17e..43c9260251 100644
--- a/samcli/local/apigw/local_apigw_service.py
+++ b/samcli/local/apigw/local_apigw_service.py
@@ -779,7 +779,7 @@ def _construct_v_2_0_event_http(
             # Flask does not parse/decode the request data. We should do it ourselves
             request_data = request_data.decode("utf-8")
 
-        query_string_dict, _ = LocalApigwService._query_string_params(flask_request)
+        query_string_dict = LocalApigwService._query_string_params_v_2_0(flask_request)
 
         cookies = LocalApigwService._event_http_cookies(flask_request)
         headers = LocalApigwService._event_http_headers(flask_request, port)
@@ -843,6 +843,33 @@ def _query_string_params(flask_request):
 
         return query_string_dict, multi_value_query_string_dict
 
+    @staticmethod
+    def _query_string_params_v_2_0(flask_request):
+        """
+        Constructs an APIGW equivalent query string dictionary using the 2.0 format
+        https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-develop-integrations-lambda.html#2.0
+
+        Parameters
+        ----------
+        flask_request request
+            Request from Flask
+
+        Returns dict (str: str)
+        -------
+            Empty dict if no query params where in the request otherwise returns a dictionary of key to value
+
+        """
+        query_string_dict = {}
+
+        # Flask returns an ImmutableMultiDict so convert to a dictionary that becomes
+        # a dict(str: list) then iterate over
+        query_string_dict = {
+            query_string_key: ",".join(query_string_list)
+            for query_string_key, query_string_list in flask_request.args.lists()
+        }
+
+        return query_string_dict
+
     @staticmethod
     def _event_headers(flask_request, port):
         """
diff --git a/samcli/local/events/api_event.py b/samcli/local/events/api_event.py
index beaf5e71b5..7f6bc74149 100644
--- a/samcli/local/events/api_event.py
+++ b/samcli/local/events/api_event.py
@@ -404,13 +404,23 @@ def __init__(
         if not isinstance(stage_variables, dict) and stage_variables is not None:
             raise TypeError("'stage_variables' must be of type dict or None")
 
+        # convert mutlivalue queries into a comma separated list per API GW documentation for format v2
+        converted_query_string_params = None
+        if query_string_params is not None:
+            converted_query_string_params = {}
+            for k, v in query_string_params.items():
+                if isinstance(v, str):
+                    converted_query_string_params[k] = v
+                else:
+                    converted_query_string_params[k] = ",".join(v)
+
         self.version = "2.0"
         self.route_key = route_key
         self.raw_path = raw_path
         self.raw_query_string = raw_query_string
         self.cookies = cookies
         self.headers = headers
-        self.query_string_params = query_string_params
+        self.query_string_params = converted_query_string_params
         self.request_context = request_context
         self.body = body
         self.path_parameters = path_parameters
diff --git a/tests/integration/local/start_api/test_start_api.py b/tests/integration/local/start_api/test_start_api.py
index 947139a224..d0e7558deb 100644
--- a/tests/integration/local/start_api/test_start_api.py
+++ b/tests/integration/local/start_api/test_start_api.py
@@ -1126,6 +1126,51 @@ def test_forward_headers_are_added_to_event(self):
         self.assertEqual(response_data.get("multiValueHeaders").get("X-Forwarded-Port"), [self.port])
 
 
+class TestServiceRequestsWithHttpApi(StartApiIntegBaseClass):
+    """
+    Test Class centered around the different requests that can happen; specifically testing the change
+    in format for mulivalue query parameters in payload format v2 (HTTP APIs)
+    """
+
+    template_path = "/testdata/start_api/swagger-template-http-api.yaml"
+
+    def setUp(self):
+        self.url = "http://127.0.0.1:{}".format(self.port)
+
+    @pytest.mark.flaky(reruns=3)
+    @pytest.mark.timeout(timeout=600, method="thread")
+    def test_request_with_multi_value_headers(self):
+        response = requests.get(
+            self.url + "/echoeventbody",
+            headers={"Content-Type": "application/x-www-form-urlencoded, image/gif"},
+            timeout=300,
+        )
+
+        self.assertEqual(response.status_code, 200)
+        response_data = response.json()
+        self.assertEqual(response_data.get("version"), "2.0")
+        self.assertIsNone(response_data.get("multiValueHeaders"))
+        self.assertEqual(
+            response_data.get("headers").get("Content-Type"), "application/x-www-form-urlencoded, image/gif"
+        )
+
+    @pytest.mark.flaky(reruns=3)
+    @pytest.mark.timeout(timeout=600, method="thread")
+    def test_request_with_list_of_query_params(self):
+        """
+        Query params given should be put into the Event to Lambda
+        """
+        response = requests.get(self.url + "/echoeventbody", params={"key": ["value", "value2"]}, timeout=300)
+
+        self.assertEqual(response.status_code, 200)
+
+        response_data = response.json()
+
+        self.assertEqual(response_data.get("version"), "2.0")
+        self.assertEqual(response_data.get("queryStringParameters"), {"key": "value,value2"})
+        self.assertIsNone(response_data.get("multiValueQueryStringParameters"))
+
+
 class TestStartApiWithStage(StartApiIntegBaseClass):
     """
     Test Class centered around the different responses that can happen in Lambda and pass through start-api
diff --git a/tests/unit/local/apigw/test_local_apigw_service.py b/tests/unit/local/apigw/test_local_apigw_service.py
index 454f1eec7f..a416b84d15 100644
--- a/tests/unit/local/apigw/test_local_apigw_service.py
+++ b/tests/unit/local/apigw/test_local_apigw_service.py
@@ -1473,6 +1473,15 @@ def test_query_string_params_with_param_value_being_non_empty_list(self):
         actual_query_string = LocalApigwService._query_string_params(request_mock)
         self.assertEqual(actual_query_string, ({"param": "b"}, {"param": ["a", "b"]}))
 
+    def test_query_string_params_v_2_0_with_param_value_being_non_empty_list(self):
+        request_mock = Mock()
+        query_param_args_mock = Mock()
+        query_param_args_mock.lists.return_value = {"param": ["a", "b"]}.items()
+        request_mock.args = query_param_args_mock
+
+        actual_query_string = LocalApigwService._query_string_params_v_2_0(request_mock)
+        self.assertEqual(actual_query_string, {"param": "a,b"})
+
 
 class TestService_construct_event_http(TestCase):
     def setUp(self):
@@ -1483,7 +1492,7 @@ def setUp(self):
         self.request_mock.get_data.return_value = b"DATA!!!!"
         self.request_mock.mimetype = "application/json"
         query_param_args_mock = Mock()
-        query_param_args_mock.lists.return_value = {"query": ["params"]}.items()
+        query_param_args_mock.lists.return_value = {"query": ["param1", "param2"]}.items()
         self.request_mock.args = query_param_args_mock
         self.request_mock.query_string = b"query=params"
         headers_mock = Mock()
@@ -1514,7 +1523,7 @@ def setUp(self):
                 "X-Forwarded-Proto": "http",
                 "X-Forwarded-Port": "3000"
             }},
-            "queryStringParameters": {{"query": "params"}},
+            "queryStringParameters": {{"query": "param1,param2"}},
             "requestContext": {{
                 "accountId": "123456789012",
                 "apiId": "1234567890",
diff --git a/tests/unit/local/events/test_api_event.py b/tests/unit/local/events/test_api_event.py
index c5c629d583..8b0aa9d8b9 100644
--- a/tests/unit/local/events/test_api_event.py
+++ b/tests/unit/local/events/test_api_event.py
@@ -516,7 +516,7 @@ def test_to_dict(self):
             "raw_query_string",
             ["cookie1=value1"],
             {"header_key": "value"},
-            {"query_string": "some query"},
+            {"query_string": "some query", "multi": ["first", "second"]},
             request_context_mock,
             "body",
             {"param": "some param"},
@@ -531,7 +531,7 @@ def test_to_dict(self):
             "rawQueryString": "raw_query_string",
             "cookies": ["cookie1=value1"],
             "headers": {"header_key": "value"},
-            "queryStringParameters": {"query_string": "some query"},
+            "queryStringParameters": {"query_string": "some query", "multi": "first,second"},
             "requestContext": request_context_mock.to_dict(),
             "body": "body",
             "pathParameters": {"param": "some param"},