diff --git a/awscrt/_test.py b/awscrt/_test.py
index 06016f955..9c4eab0d6 100644
--- a/awscrt/_test.py
+++ b/awscrt/_test.py
@@ -10,6 +10,8 @@
 import time
 import types
 
+from awscrt.io import ClientBootstrap, DefaultHostResolver, EventLoopGroup
+
 
 def native_memory_usage() -> int:
     """
@@ -80,6 +82,10 @@ def check_for_leaks(*, timeout_sec=10.0):
             if the test results will be made public as it may result in secrets
             being leaked.
     """
+    ClientBootstrap.release_static_default()
+    EventLoopGroup.release_static_default()
+    DefaultHostResolver.release_static_default()
+
     if os.getenv('AWS_CRT_MEMORY_TRACING') != '2':
         raise RuntimeError("environment variable AWS_CRT_MEMORY_TRACING=2 must be set for accurate leak checks")
 
diff --git a/awscrt/auth.py b/awscrt/auth.py
index a3f193045..c4262dc16 100644
--- a/awscrt/auth.py
+++ b/awscrt/auth.py
@@ -125,7 +125,7 @@ def __init__(self, binding):
         self._binding = binding
 
     @classmethod
-    def new_default_chain(cls, client_bootstrap):
+    def new_default_chain(cls, client_bootstrap=None):
         """
         Create the default provider chain used by most AWS SDKs.
 
@@ -137,12 +137,16 @@ def new_default_chain(cls, client_bootstrap):
         4.  (conditional, on by default) EC2 Instance Metadata
 
         Args:
-            client_bootstrap (ClientBootstrap): Client bootstrap to use when initiating socket connection.
+            client_bootstrap (Optional[ClientBootstrap]): Client bootstrap to use when initiating socket connection.
+                If not set, uses the default static ClientBootstrap instead.
 
         Returns:
             AwsCredentialsProvider:
         """
-        assert isinstance(client_bootstrap, ClientBootstrap)
+        assert isinstance(client_bootstrap, ClientBootstrap) or client_bootstrap is None
+
+        if client_bootstrap is None:
+            client_bootstrap = ClientBootstrap.get_or_create_static_default()
 
         binding = _awscrt.credentials_provider_new_chain_default(client_bootstrap)
         return cls(binding)
@@ -170,7 +174,7 @@ def new_static(cls, access_key_id, secret_access_key, session_token=None):
     @classmethod
     def new_profile(
             cls,
-            client_bootstrap,
+            client_bootstrap=None,
             profile_name=None,
             config_filepath=None,
             credentials_filepath=None):
@@ -179,7 +183,8 @@ def new_profile(
         loaded from the aws credentials file.
 
         Args:
-            client_bootstrap (ClientBootstrap): Client bootstrap to use when initiating socket connection.
+            client_bootstrap (Optional[ClientBootstrap]): Client bootstrap to use when initiating socket connection.
+                If not set, uses the static default ClientBootstrap instead.
 
             profile_name (Optional[str]): Name of profile to use.
                 If not set, uses value from AWS_PROFILE environment variable.
@@ -196,11 +201,14 @@ def new_profile(
         Returns:
             AwsCredentialsProvider:
         """
-        assert isinstance(client_bootstrap, ClientBootstrap)
+        assert isinstance(client_bootstrap, ClientBootstrap) or client_bootstrap is None
         assert isinstance(profile_name, str) or profile_name is None
         assert isinstance(config_filepath, str) or config_filepath is None
         assert isinstance(credentials_filepath, str) or credentials_filepath is None
 
+        if client_bootstrap is None:
+            client_bootstrap = ClientBootstrap.get_or_create_static_default()
+
         binding = _awscrt.credentials_provider_new_profile(
             client_bootstrap, profile_name, config_filepath, credentials_filepath)
         return cls(binding)
diff --git a/awscrt/eventstream/rpc.py b/awscrt/eventstream/rpc.py
index 29974b694..6c80268ac 100644
--- a/awscrt/eventstream/rpc.py
+++ b/awscrt/eventstream/rpc.py
@@ -258,7 +258,7 @@ def connect(
             handler: ClientConnectionHandler,
             host_name: str,
             port: int,
-            bootstrap: ClientBootstrap,
+            bootstrap: ClientBootstrap = None,
             socket_options: Optional[SocketOptions] = None,
             tls_connection_options: Optional[TlsConnectionOptions] = None) -> Future:
         """Asynchronously establish a new ClientConnection.
@@ -271,6 +271,7 @@ def connect(
             port: Connect to port.
 
             bootstrap: Client bootstrap to use when initiating socket connection.
+                If None is provided, the default singleton is used.
 
             socket_options: Optional socket options.
                 If None is provided, then default options are used.
@@ -297,6 +298,9 @@ def connect(
         # Connection is not made available to user until setup callback fires
         connection = cls(host_name, port, handler)
 
+        if not bootstrap:
+            bootstrap = ClientBootstrap.get_or_create_static_default()
+
         # connection._binding is set within the following call */
         _awscrt.event_stream_rpc_client_connection_connect(
             host_name,
diff --git a/awscrt/http.py b/awscrt/http.py
index 5ffe9a6f3..258cdaaa8 100644
--- a/awscrt/http.py
+++ b/awscrt/http.py
@@ -11,7 +11,7 @@
 from concurrent.futures import Future
 from awscrt import NativeResource
 import awscrt.exceptions
-from awscrt.io import ClientBootstrap, EventLoopGroup, DefaultHostResolver, InputStream, TlsConnectionOptions, SocketOptions
+from awscrt.io import ClientBootstrap, InputStream, TlsConnectionOptions, SocketOptions
 from enum import IntEnum
 
 
@@ -82,7 +82,7 @@ class HttpClientConnection(HttpConnectionBase):
     def new(cls,
             host_name,
             port,
-            bootstrap,
+            bootstrap=None,
             socket_options=None,
             tls_connection_options=None,
             proxy_options=None):
@@ -94,7 +94,8 @@ def new(cls,
 
             port (int): Connect to port.
 
-            bootstrap (ClientBootstrap): Client bootstrap to use when initiating socket connection.
+            bootstrap (Optional [ClientBootstrap]): Client bootstrap to use when initiating socket connection.
+                If None is provided, the default singleton is used.
 
             socket_options (Optional[SocketOptions]): Optional socket options.
                 If None is provided, then default options are used.
@@ -124,9 +125,7 @@ def new(cls,
                 socket_options = SocketOptions()
 
             if not bootstrap:
-                event_loop_group = EventLoopGroup(1)
-                host_resolver = DefaultHostResolver(event_loop_group)
-                bootstrap = ClientBootstrap(event_loop_group, host_resolver)
+                bootstrap = ClientBootstrap.get_or_create_static_default()
 
             connection = cls()
             connection._host_name = host_name
diff --git a/awscrt/io.py b/awscrt/io.py
index 616e1ada9..c3e1f1916 100644
--- a/awscrt/io.py
+++ b/awscrt/io.py
@@ -60,6 +60,8 @@ class EventLoopGroup(NativeResource):
             EventLoopGroup object is destroyed.
     """
 
+    _static_event_loop_group = None
+    _static_event_loop_group_lock = threading.Lock()
     __slots__ = ('shutdown_event')
 
     def __init__(self, num_threads=None, cpu_group=None):
@@ -83,6 +85,18 @@ def on_shutdown():
         self.shutdown_event = shutdown_event
         self._binding = _awscrt.event_loop_group_new(num_threads, is_pinned, cpu_group, on_shutdown)
 
+    @staticmethod
+    def get_or_create_static_default():
+        with EventLoopGroup._static_event_loop_group_lock:
+            if EventLoopGroup._static_event_loop_group is None:
+                EventLoopGroup._static_event_loop_group = EventLoopGroup()
+            return EventLoopGroup._static_event_loop_group
+
+    @staticmethod
+    def release_static_default():
+        with EventLoopGroup._static_event_loop_group_lock:
+            EventLoopGroup._static_event_loop_group = None
+
 
 class HostResolverBase(NativeResource):
     """DNS host resolver."""
@@ -96,6 +110,9 @@ class DefaultHostResolver(HostResolverBase):
         event_loop_group (EventLoopGroup): EventLoopGroup to use.
         max_hosts(int): Max host names to cache.
     """
+
+    _static_host_resolver = None
+    _static_host_resolver_lock = threading.Lock()
     __slots__ = ()
 
     def __init__(self, event_loop_group, max_hosts=16):
@@ -104,6 +121,19 @@ def __init__(self, event_loop_group, max_hosts=16):
         super().__init__()
         self._binding = _awscrt.host_resolver_new_default(max_hosts, event_loop_group)
 
+    @staticmethod
+    def get_or_create_static_default():
+        with DefaultHostResolver._static_host_resolver_lock:
+            if DefaultHostResolver._static_host_resolver is None:
+                DefaultHostResolver._static_host_resolver = DefaultHostResolver(
+                    EventLoopGroup.get_or_create_static_default())
+            return DefaultHostResolver._static_host_resolver
+
+    @staticmethod
+    def release_static_default():
+        with DefaultHostResolver._static_host_resolver_lock:
+            DefaultHostResolver._static_host_resolver = None
+
 
 class ClientBootstrap(NativeResource):
     """Handles creation and setup of client socket connections.
@@ -117,6 +147,9 @@ class ClientBootstrap(NativeResource):
             internal resources finish shutting down.
             Shutdown begins when the ClientBootstrap object is destroyed.
     """
+
+    _static_client_bootstrap = None
+    _static_client_bootstrap_lock = threading.Lock()
     __slots__ = ('shutdown_event')
 
     def __init__(self, event_loop_group, host_resolver):
@@ -133,6 +166,20 @@ def on_shutdown():
         self.shutdown_event = shutdown_event
         self._binding = _awscrt.client_bootstrap_new(event_loop_group, host_resolver, on_shutdown)
 
+    @staticmethod
+    def get_or_create_static_default():
+        with ClientBootstrap._static_client_bootstrap_lock:
+            if ClientBootstrap._static_client_bootstrap is None:
+                ClientBootstrap._static_client_bootstrap = ClientBootstrap(
+                    EventLoopGroup.get_or_create_static_default(),
+                    DefaultHostResolver.get_or_create_static_default())
+            return ClientBootstrap._static_client_bootstrap
+
+    @staticmethod
+    def release_static_default():
+        with ClientBootstrap._static_client_bootstrap_lock:
+            ClientBootstrap._static_client_bootstrap = None
+
 
 def _read_binary_file(filepath):
     with open(filepath, mode='rb') as fh:
diff --git a/awscrt/mqtt.py b/awscrt/mqtt.py
index 39c9b0b96..17b5a5e25 100644
--- a/awscrt/mqtt.py
+++ b/awscrt/mqtt.py
@@ -130,7 +130,8 @@ class Client(NativeResource):
     """MQTT client.
 
     Args:
-        bootstrap (ClientBootstrap): Client bootstrap to use when initiating new socket connections.
+        bootstrap (Optional [ClientBootstrap]): Client bootstrap to use when initiating new socket connections.
+            If None is provided, the default singleton is used.
 
         tls_ctx (Optional[ClientTlsContext]): TLS context for secure socket connections.
             If None is provided, then an unencrypted connection is used.
@@ -138,12 +139,14 @@ class Client(NativeResource):
 
     __slots__ = ('tls_ctx')
 
-    def __init__(self, bootstrap, tls_ctx=None):
-        assert isinstance(bootstrap, ClientBootstrap)
+    def __init__(self, bootstrap=None, tls_ctx=None):
+        assert isinstance(bootstrap, ClientBootstrap) or bootstrap is None
         assert tls_ctx is None or isinstance(tls_ctx, ClientTlsContext)
 
         super().__init__()
         self.tls_ctx = tls_ctx
+        if not bootstrap:
+            bootstrap = ClientBootstrap.get_or_create_static_default()
         self._binding = _awscrt.mqtt_client_new(bootstrap, tls_ctx)
 
 
@@ -435,6 +438,7 @@ def on_disconnect():
 
         try:
             _awscrt.mqtt_client_connection_disconnect(self._binding, on_disconnect)
+
         except Exception as e:
             future.set_exception(e)
 
diff --git a/awscrt/s3.py b/awscrt/s3.py
index e13459851..73c008ba4 100644
--- a/awscrt/s3.py
+++ b/awscrt/s3.py
@@ -54,7 +54,8 @@ class S3Client(NativeResource):
     """S3 client
 
     Keyword Args:
-        bootstrap (ClientBootstrap): Client bootstrap to use when initiating socket connection.
+        bootstrap (Optional [ClientBootstrap]): Client bootstrap to use when initiating socket connection.
+            If None is provided, the default singleton is used.
 
         region (str): Region that the S3 bucket lives in.
 
@@ -94,7 +95,7 @@ def __init__(
             tls_connection_options=None,
             part_size=None,
             throughput_target_gbps=None):
-        assert isinstance(bootstrap, ClientBootstrap)
+        assert isinstance(bootstrap, ClientBootstrap) or bootstrap is None
         assert isinstance(region, str)
         assert isinstance(credential_provider, AwsCredentialsProvider) or credential_provider is None
         assert isinstance(tls_connection_options, TlsConnectionOptions) or tls_connection_options is None
@@ -113,6 +114,9 @@ def on_shutdown():
             shutdown_event.set()
         self._region = region
         self.shutdown_event = shutdown_event
+
+        if not bootstrap:
+            bootstrap = ClientBootstrap.get_or_create_static_default()
         s3_client_core = _S3ClientCore(bootstrap, credential_provider, tls_connection_options)
 
         # C layer uses 0 to indicate defaults
diff --git a/test/test_io.py b/test/test_io.py
index a967c0d26..a5219a591 100644
--- a/test/test_io.py
+++ b/test/test_io.py
@@ -25,12 +25,35 @@ def test_shutdown_complete(self):
         del event_loop_group
         self.assertTrue(shutdown_event.wait(TIMEOUT))
 
+    def test_init_defaults_singleton(self):
+        event_loop_group = EventLoopGroup.get_or_create_static_default()
+
+    def test_init_defaults_singleton_is_singleton(self):
+        event_loop_group_one = EventLoopGroup.get_or_create_static_default()
+        event_loop_group_two = EventLoopGroup.get_or_create_static_default()
+        self.assertTrue(event_loop_group_one == event_loop_group_two)
+
+    def test_shutdown_complete_singleton(self):
+        event_loop_group = EventLoopGroup.get_or_create_static_default()
+        shutdown_event = event_loop_group.shutdown_event
+        del event_loop_group
+        EventLoopGroup.release_static_default()
+        self.assertTrue(shutdown_event.wait(TIMEOUT))
+
 
 class DefaultHostResolverTest(NativeResourceTest):
     def test_init(self):
         event_loop_group = EventLoopGroup()
         host_resolver = DefaultHostResolver(event_loop_group)
 
+    def test_init_singleton(self):
+        host_resolver = DefaultHostResolver.get_or_create_static_default()
+
+    def test_init_singleton_is_singleton(self):
+        host_resolver_one = DefaultHostResolver.get_or_create_static_default()
+        host_resolver_two = DefaultHostResolver.get_or_create_static_default()
+        self.assertTrue(host_resolver_one == host_resolver_two)
+
 
 class ClientBootstrapTest(NativeResourceTest):
     def test_create_destroy(self):
@@ -43,6 +66,20 @@ def test_create_destroy(self):
         del bootstrap
         self.assertTrue(bootstrap_shutdown_event.wait(TIMEOUT))
 
+    def test_create_destroy_singleton(self):
+        bootstrap = ClientBootstrap.get_or_create_static_default()
+
+        # ensure shutdown_event fires
+        bootstrap_shutdown_event = bootstrap.shutdown_event
+        del bootstrap
+        ClientBootstrap.release_static_default()
+        self.assertTrue(bootstrap_shutdown_event.wait(TIMEOUT))
+
+    def test_init_singleton_is_singleton(self):
+        client_one = ClientBootstrap.get_or_create_static_default()
+        client_two = ClientBootstrap.get_or_create_static_default()
+        self.assertTrue(client_one == client_two)
+
 
 class ClientTlsContextTest(NativeResourceTest):
     def test_init_defaults(self):
diff --git a/test/test_mqtt.py b/test/test_mqtt.py
index 25a49d74c..566f90512 100644
--- a/test/test_mqtt.py
+++ b/test/test_mqtt.py
@@ -57,11 +57,8 @@ class MqttConnectionTest(NativeResourceTest):
     TEST_TOPIC = '/test/me/senpai'
     TEST_MSG = 'NOTICE ME!'.encode('utf8')
 
-    def _create_connection(self, auth_type=AuthType.CERT_AND_KEY):
+    def _create_connection(self, auth_type=AuthType.CERT_AND_KEY, use_static_singletons=False):
         config = Config(auth_type)
-        elg = EventLoopGroup()
-        resolver = DefaultHostResolver(elg)
-        bootstrap = ClientBootstrap(elg, resolver)
 
         if auth_type == AuthType.CERT_AND_KEY:
             tls_opts = TlsContextOptions.create_client_with_mtls_from_path(config.cert_path, config.key_path)
@@ -89,7 +86,14 @@ def _create_connection(self, auth_type=AuthType.CERT_AND_KEY):
                     # re-raise exception
                     raise
 
-        client = Client(bootstrap, tls)
+        if use_static_singletons:
+            client = Client(tls_ctx=tls)
+        else:
+            elg = EventLoopGroup()
+            resolver = DefaultHostResolver(elg)
+            bootstrap = ClientBootstrap(elg, resolver)
+            client = Client(bootstrap, tls)
+
         connection = Connection(
             client=client,
             client_id=create_client_id(),
@@ -212,6 +216,16 @@ def on_sub_message(topic, payload):
         # disconnect
         connection.disconnect().result(TIMEOUT)
 
+    def test_connect_disconnect_with_default_singletons(self):
+        connection = self._create_connection(use_static_singletons=True)
+        connection.connect().result(TIMEOUT)
+        connection.disconnect().result(TIMEOUT)
+
+        # free singletons
+        ClientBootstrap.release_static_default()
+        EventLoopGroup.release_static_default()
+        DefaultHostResolver.release_static_default()
+
 
 if __name__ == 'main':
     unittest.main()