diff --git a/awscrt/mqtt.py b/awscrt/mqtt.py
index 7529168ea..675f57688 100644
--- a/awscrt/mqtt.py
+++ b/awscrt/mqtt.py
@@ -15,7 +15,7 @@
 from awscrt.http import HttpProxyOptions, HttpRequest
 from awscrt.io import ClientBootstrap, ClientTlsContext, SocketOptions
 from dataclasses import dataclass
-from awscrt.mqtt5 import Client as Mqtt5Client
+from awscrt.mqtt5 import Client as Mqtt5Client, _get_awsiot_metrics_str
 
 
 class QoS(IntEnum):
@@ -330,6 +330,8 @@ class Connection(NativeResource):
 
         proxy_options (Optional[awscrt.http.HttpProxyOptions]):
             Optional proxy options for all connections.
+
+        enable_aws_metrics (bool): If true, append AWS IoT metrics to the username. (Default to true)
         """
 
     def __init__(self,
@@ -355,7 +357,8 @@ def __init__(self,
                  proxy_options=None,
                  on_connection_success=None,
                  on_connection_failure=None,
-                 on_connection_closed=None
+                 on_connection_closed=None,
+                 enable_aws_metrics=True
                  ):
 
         assert isinstance(client, Client) or isinstance(client, Mqtt5Client)
@@ -404,6 +407,11 @@ def __init__(self,
         self.ping_timeout_ms = ping_timeout_ms
         self.protocol_operation_timeout_ms = protocol_operation_timeout_ms
         self.will = will
+
+        if enable_aws_metrics:
+            username = username if username else ""
+            username += _get_awsiot_metrics_str(username)
+
         self.username = username
         self.password = password
         self.socket_options = socket_options if socket_options else SocketOptions()
diff --git a/awscrt/mqtt5.py b/awscrt/mqtt5.py
index 7c5e4f31f..5d1eba7f4 100644
--- a/awscrt/mqtt5.py
+++ b/awscrt/mqtt5.py
@@ -16,6 +16,40 @@
 from collections.abc import Sequence
 from inspect import signature
 
+# Global variable to cache metrics string
+_metrics_str = None
+
+
+def _get_awsiot_metrics_str(current_username=""):
+    global _metrics_str
+
+    username_has_query = False
+    if current_username.find("?") != -1:
+        username_has_query = True
+    # The SDK query is already set, skip adding it again
+    if username_has_query and current_username.find("SDK=") != -1:
+        return ""
+
+    if _metrics_str is None:
+        try:
+            import importlib.metadata
+            try:
+                version = importlib.metadata.version("awscrt")
+                _metrics_str = "SDK=CRTPython&Version={}&Platform={}".format(
+                    version, _awscrt.get_platform_build_os_string())
+            except importlib.metadata.PackageNotFoundError:
+                _metrics_str = "SDK=CRTPython&Version=dev&Platform={}".format(_awscrt.get_platform_build_os_string())
+        except BaseException:
+            _metrics_str = ""
+
+    if not _metrics_str == "":
+        if username_has_query:
+            return "&" + _metrics_str
+        else:
+            return "?" + _metrics_str
+    else:
+        return ""
+
 
 class QoS(IntEnum):
     """MQTT message delivery quality of service.
@@ -1338,6 +1372,7 @@ class ClientOptions:
         on_lifecycle_event_connection_success_fn (Callable[[LifecycleConnectSuccessData],]): Callback for Lifecycle Event Connection Success.
         on_lifecycle_event_connection_failure_fn (Callable[[LifecycleConnectFailureData],]): Callback for Lifecycle Event Connection Failure.
         on_lifecycle_event_disconnection_fn (Callable[[LifecycleDisconnectData],]): Callback for Lifecycle Event Disconnection.
+        enable_aws_metrics (bool): Whether to append AWS IoT metrics to the username field during CONNECT. Default: True
     """
     host_name: str
     port: int = None
@@ -1364,6 +1399,7 @@ class ClientOptions:
     on_lifecycle_event_connection_success_fn: Callable[[LifecycleConnectSuccessData], None] = None
     on_lifecycle_event_connection_failure_fn: Callable[[LifecycleConnectFailureData], None] = None
     on_lifecycle_event_disconnection_fn: Callable[[LifecycleDisconnectData], None] = None
+    enable_aws_metrics: bool = True
 
 
 def _check_callback(callback):
@@ -1753,6 +1789,11 @@ def __init__(self, client_options: ClientOptions):
             is_will_none = False
             will = connect_options.will
 
+        username = connect_options.username
+        if client_options.enable_aws_metrics:
+            username = username if username else ""
+            username += _get_awsiot_metrics_str(username)
+        connect_options.username = username
         websocket_is_none = client_options.websocket_handshake_transform is None
         self.tls_ctx = client_options.tls_ctx
         self._binding = _awscrt.mqtt5_client_new(self,
diff --git a/crt/aws-c-common b/crt/aws-c-common
index 31578beb2..7a67e7748 160000
--- a/crt/aws-c-common
+++ b/crt/aws-c-common
@@ -1 +1 @@
-Subproject commit 31578beb2309330fece3fb3a66035a568a2641e7
+Subproject commit 7a67e7748644ea01161215dc457165f96259dd8e
diff --git a/source/common.c b/source/common.c
index cd1b19ef6..236fc2945 100644
--- a/source/common.c
+++ b/source/common.c
@@ -26,6 +26,14 @@ PyObject *aws_py_get_cpu_count_for_group(PyObject *self, PyObject *args) {
     return PyLong_FromSize_t(count);
 }
 
+PyObject *aws_py_get_platform_build_os_string(PyObject *self, PyObject *args) {
+    (void)self;
+    (void)args;
+
+    struct aws_byte_cursor os_string = aws_get_platform_build_os_string();
+    return PyUnicode_FromAwsByteCursor(&os_string);
+}
+
 PyObject *aws_py_thread_join_all_managed(PyObject *self, PyObject *args) {
     (void)self;
 
diff --git a/source/common.h b/source/common.h
index 48df0cf6f..45a23d09b 100644
--- a/source/common.h
+++ b/source/common.h
@@ -13,6 +13,7 @@
 
 PyObject *aws_py_get_cpu_group_count(PyObject *self, PyObject *args);
 PyObject *aws_py_get_cpu_count_for_group(PyObject *self, PyObject *args);
+PyObject *aws_py_get_platform_build_os_string(PyObject *self, PyObject *args);
 
 PyObject *aws_py_thread_join_all_managed(PyObject *self, PyObject *args);
 
diff --git a/source/module.c b/source/module.c
index be4afdca1..b8919064c 100644
--- a/source/module.c
+++ b/source/module.c
@@ -767,6 +767,7 @@ static PyMethodDef s_module_methods[] = {
     AWS_PY_METHOD_DEF(get_corresponding_builtin_exception, METH_VARARGS),
     AWS_PY_METHOD_DEF(get_cpu_group_count, METH_VARARGS),
     AWS_PY_METHOD_DEF(get_cpu_count_for_group, METH_VARARGS),
+    AWS_PY_METHOD_DEF(get_platform_build_os_string, METH_VARARGS),
     AWS_PY_METHOD_DEF(native_memory_usage, METH_NOARGS),
     AWS_PY_METHOD_DEF(native_memory_dump, METH_NOARGS),
     AWS_PY_METHOD_DEF(thread_join_all_managed, METH_VARARGS),
diff --git a/test/test_mqtt.py b/test/test_mqtt.py
index f8435316e..ef54b6d94 100644
--- a/test/test_mqtt.py
+++ b/test/test_mqtt.py
@@ -629,7 +629,8 @@ def _test_mqtt311_direct_connect_basic_auth(self):
             host_name=input_host_name,
             port=input_port,
             username=input_username,
-            password=input_password)
+            password=input_password,
+            enable_aws_metrics=False)  # Disable AWS metrics for basic auth on non-AWS broker
         connection.connect().result(TIMEOUT)
         connection.disconnect().result(TIMEOUT)
 
@@ -760,7 +761,8 @@ def sign_function(transform_args, **kwargs):
             username=input_username,
             password=input_password,
             use_websockets=True,
-            websocket_handshake_transform=sign_function)
+            websocket_handshake_transform=sign_function,
+            enable_aws_metrics=False)   # Disable AWS metrics for basic auth on non-AWS broker
         connection.connect().result(TIMEOUT)
         connection.disconnect().result(TIMEOUT)
 
diff --git a/test/test_mqtt5.py b/test/test_mqtt5.py
index 83ee5928a..db0a5f73b 100644
--- a/test/test_mqtt5.py
+++ b/test/test_mqtt5.py
@@ -229,7 +229,8 @@ def _test_direct_connect_basic_auth(self):
         client_options = mqtt5.ClientOptions(
             host_name=input_host_name,
             port=input_port,
-            connect_options=connect_options
+            connect_options=connect_options,
+            enable_aws_metrics=False    # Disable AWS metrics for basic auth on non-AWS broker
         )
         callbacks = Mqtt5TestCallbacks()
         client = self._create_client(client_options=client_options, callbacks=callbacks)
@@ -416,7 +417,8 @@ def _test_websocket_connect_basic_auth(self):
         client_options = mqtt5.ClientOptions(
             host_name=input_host_name,
             port=input_port,
-            connect_options=connect_options
+            connect_options=connect_options,
+            enable_aws_metrics=False    # Disable AWS metrics for basic auth on non-AWS broker
         )
         callbacks = Mqtt5TestCallbacks()
         client_options.websocket_handshake_transform = callbacks.ws_handshake_transform
@@ -615,7 +617,8 @@ def test_connect_with_incorrect_basic_authentication_credentials(self):
         client_options = mqtt5.ClientOptions(
             host_name=input_host_name,
             port=input_port,
-            connect_options=connect_options
+            connect_options=connect_options,
+            enable_aws_metrics=False    # Disable AWS metrics for basic auth on non-AWS broker
         )
         callbacks = Mqtt5TestCallbacks()
         client = self._create_client(client_options=client_options, callbacks=callbacks)