diff --git a/docs/client.rst b/docs/client.rst
index 5350bcbc..1a55b71e 100644
--- a/docs/client.rst
+++ b/docs/client.rst
@@ -533,6 +533,11 @@ coroutines if desired::
 
     sio.register_namespace(MyCustomNamespace('/chat'))
 
+A catch-all class-based namespace handler can be defined by passing ``'*'`` as
+the namespace during registration::
+
+    sio.register_namespace(MyCustomNamespace('*'))
+
 When class-based namespaces are used, any events received by the client are
 dispatched to a method named as the event name with the ``on_`` prefix. For
 example, event ``my_event`` will be handled by a method named ``on_my_event``.
diff --git a/docs/server.rst b/docs/server.rst
index b53647ae..2393b9b9 100644
--- a/docs/server.rst
+++ b/docs/server.rst
@@ -361,6 +361,11 @@ if desired::
 
     sio.register_namespace(MyCustomNamespace('/test'))
 
+A catch-all class-based namespace handler can be defined by passing ``'*'`` as
+the namespace during registration::
+
+    sio.register_namespace(MyCustomNamespace('*'))
+
 When class-based namespaces are used, any events received by the server are
 dispatched to a method named as the event name with the ``on_`` prefix. For
 example, event ``my_event`` will be handled by a method named ``on_my_event``.
diff --git a/src/socketio/base_client.py b/src/socketio/base_client.py
index cd007ccc..1becf914 100644
--- a/src/socketio/base_client.py
+++ b/src/socketio/base_client.py
@@ -106,13 +106,15 @@ def on(self, event, handler=None, namespace=None):
 
         :param event: The event name. It can be any string. The event names
                       ``'connect'``, ``'message'`` and ``'disconnect'`` are
-                      reserved and should not be used.
+                      reserved and should not be used. The ``'*'`` event name
+                      can be used to define a catch-all event handler.
         :param handler: The function that should be invoked to handle the
                         event. When this parameter is not given, the method
                         acts as a decorator for the handler function.
         :param namespace: The Socket.IO namespace for the event. If this
                           argument is omitted the handler is associated with
-                          the default namespace.
+                          the default namespace. A catch-all namespace can be
+                          defined by passing ``'*'`` as the namespace.
 
         Example usage::
 
@@ -127,12 +129,21 @@ def message_handler(msg):
                 sio.send( 'response')
             sio.on('message', message_handler)
 
-        The ``'connect'`` event handler receives no arguments. The
-        ``'message'`` handler and handlers for custom event names receive the
-        message payload as only argument. Any values returned from a message
-        handler will be passed to the client's acknowledgement callback
-        function if it exists. The ``'disconnect'`` handler does not take
-        arguments.
+        The arguments passed to the handler function depend on the event type:
+
+        - The ``'connect'`` event handler does not take arguments.
+        - The ``'disconnect'`` event handler does not take arguments.
+        - The ``'message'`` handler and handlers for custom event names receive
+          the message payload as only argument. Any values returned from a
+          message handler will be passed to the client's acknowledgement
+          callback function if it exists.
+        - A catch-all event handler receives the event name as first argument,
+          followed by any arguments specific to the event.
+        - A catch-all namespace event handler receives the namespace as first
+          argument, followed by any arguments specific to the event.
+        - A combined catch-all namespace and catch-all event handler receives
+          the event name as first argument and the namespace as second
+          argument, followed by any arguments specific to the event.
         """
         namespace = namespace or '/'
 
diff --git a/src/socketio/base_server.py b/src/socketio/base_server.py
index 213158be..0a344292 100644
--- a/src/socketio/base_server.py
+++ b/src/socketio/base_server.py
@@ -71,13 +71,15 @@ def on(self, event, handler=None, namespace=None):
 
         :param event: The event name. It can be any string. The event names
                       ``'connect'``, ``'message'`` and ``'disconnect'`` are
-                      reserved and should not be used.
+                      reserved and should not be used. The ``'*'`` event name
+                      can be used to define a catch-all event handler.
         :param handler: The function that should be invoked to handle the
                         event. When this parameter is not given, the method
                         acts as a decorator for the handler function.
         :param namespace: The Socket.IO namespace for the event. If this
                           argument is omitted the handler is associated with
-                          the default namespace.
+                          the default namespace. A catch-all namespace can be
+                          defined by passing ``'*'`` as the namespace.
 
         Example usage::
 
@@ -94,14 +96,23 @@ def message_handler(sid, msg):
                 sio.send(sid, 'response')
             socket_io.on('message', namespace='/chat', handler=message_handler)
 
-        The handler function receives the ``sid`` (session ID) for the
-        client as first argument. The ``'connect'`` event handler receives the
-        WSGI environment as a second argument, and can return ``False`` to
-        reject the connection. The ``'message'`` handler and handlers for
-        custom event names receive the message payload as a second argument.
-        Any values returned from a message handler will be passed to the
-        client's acknowledgement callback function if it exists. The
-        ``'disconnect'`` handler does not take a second argument.
+        The arguments passed to the handler function depend on the event type:
+
+        - The ``'connect'`` event handler receives the ``sid`` (session ID) for
+          the client and the WSGI environment dictionary as arguments.
+        - The ``'disconnect'`` handler receives the ``sid`` for the client as
+          only argument.
+        - The ``'message'`` handler and handlers for custom event names receive
+          the ``sid`` for the client and the message payload as arguments. Any
+          values returned from a message handler will be passed to the client's
+          acknowledgement callback function if it exists.
+        - A catch-all event handler receives the event name as first argument,
+          followed by any arguments specific to the event.
+        - A catch-all namespace event handler receives the namespace as first
+          argument, followed by any arguments specific to the event.
+        - A combined catch-all namespace and catch-all event handler receives
+          the event name as first argument and the namespace as second
+          argument, followed by any arguments specific to the event.
         """
         namespace = namespace or '/'