diff --git a/python/ql/lib/change-notes/2025-11-26-socketio.md b/python/ql/lib/change-notes/2025-11-26-socketio.md
new file mode 100644
index 000000000000..e58bec0bbc12
--- /dev/null
+++ b/python/ql/lib/change-notes/2025-11-26-socketio.md
@@ -0,0 +1,4 @@
+---
+category: minorAnalysis
+---
+* Remote flow sources for the `python-socketio` package have been modeled.
\ No newline at end of file
diff --git a/python/ql/lib/semmle/python/Frameworks.qll b/python/ql/lib/semmle/python/Frameworks.qll
index 955385141f7f..7694419b41d5 100644
--- a/python/ql/lib/semmle/python/Frameworks.qll
+++ b/python/ql/lib/semmle/python/Frameworks.qll
@@ -78,6 +78,7 @@ private import semmle.python.frameworks.Sanic
 private import semmle.python.frameworks.ServerLess
 private import semmle.python.frameworks.Setuptools
 private import semmle.python.frameworks.Simplejson
+private import semmle.python.frameworks.Socketio
 private import semmle.python.frameworks.SqlAlchemy
 private import semmle.python.frameworks.Starlette
 private import semmle.python.frameworks.Stdlib
diff --git a/python/ql/lib/semmle/python/frameworks/Socketio.qll b/python/ql/lib/semmle/python/frameworks/Socketio.qll
new file mode 100644
index 000000000000..4006dcfbe7d8
--- /dev/null
+++ b/python/ql/lib/semmle/python/frameworks/Socketio.qll
@@ -0,0 +1,119 @@
+/**
+ * Provides definitions and modeling for the `python-socketio` PyPI package.
+ * See https://python-socketio.readthedocs.io/en/stable/.
+ */
+
+private import python
+private import semmle.python.dataflow.new.TaintTracking
+private import semmle.python.dataflow.new.RemoteFlowSources
+private import semmle.python.Concepts
+private import semmle.python.ApiGraphs
+private import semmle.python.frameworks.internal.PoorMansFunctionResolution
+
+/**
+ * Provides models for the `python-socketio` PyPI package.
+ * See https://python-socketio.readthedocs.io/en/stable/.
+ */
+module SocketIO {
+  /** Provides models for socketio `Server` and `AsyncServer` classes. */
+  module Server {
+    /** Gets an instance of a socketio `Server` or `AsyncServer`. */
+    API::Node server() {
+      result = API::moduleImport("socketio").getMember(["Server", "AsyncServer"]).getAnInstance()
+    }
+
+    /** Gets a decorator that indicates a socketio event handler. */
+    private API::Node serverEventAnnotation() {
+      result = server().getMember("event")
+      or
+      result = server().getMember("on").getReturn()
+    }
+
+    private class EventHandler extends Http::Server::RequestHandler::Range {
+      EventHandler() {
+        serverEventAnnotation().getAValueReachableFromSource().asExpr() = this.getADecorator()
+        or
+        exists(DataFlow::CallCfgNode c, DataFlow::Node arg |
+          c = server().getMember("on").getACall()
+        |
+          (
+            arg = c.getArg(1)
+            or
+            arg = c.getArgByName("handler")
+          ) and
+          poorMansFunctionTracker(this) = arg
+        )
+      }
+
+      override Parameter getARoutedParameter() {
+        result = this.getAnArg() and
+        not result = this.getArg(0) // First parameter is `sid`, which is not a remote flow source as it cannot be controlled by the client.
+      }
+
+      override string getFramework() { result = "socketio" }
+    }
+
+    private class CallbackArgument extends DataFlow::Node {
+      CallbackArgument() {
+        exists(DataFlow::CallCfgNode c |
+          c = [server(), Namespace::instance()].getMember(["emit", "send"]).getACall()
+        |
+          this = c.getArgByName("callback")
+        )
+      }
+    }
+
+    private class CallbackHandler extends Http::Server::RequestHandler::Range {
+      CallbackHandler() { any(CallbackArgument ca) = poorMansFunctionTracker(this) }
+
+      override Parameter getARoutedParameter() { result = this.getAnArg() }
+
+      override string getFramework() { result = "socketio" }
+    }
+
+    private class SocketIOCall extends RemoteFlowSource::Range {
+      SocketIOCall() { this = [server(), Namespace::instance()].getMember("call").getACall() }
+
+      override string getSourceType() { result = "socketio call" }
+    }
+  }
+
+  /** Provides modeling for socketio server Namespace/AsyncNamespace classes. */
+  module Namespace {
+    /** Gets a reference to the `socketio.Namespace` or `socketio.AsyncNamespace` classes or any subclass. */
+    API::Node subclassRef() {
+      result =
+        API::moduleImport("socketio").getMember(["Namespace", "AsyncNamespace"]).getASubclass*()
+    }
+
+    /** Gets a reference to an instance of a subclass of `socketio.Namespace` or `socketio.AsyncNamespace`. */
+    API::Node instance() {
+      result = subclassRef().getAnInstance()
+      or
+      result = subclassRef().getAMember().getSelfParameter()
+    }
+
+    /** A socketio Namespace class. */
+    class NamespaceClass extends Class {
+      NamespaceClass() { this.getABase() = subclassRef().asSource().asExpr() }
+
+      /** Gets a handler for socketio events. */
+      Function getAnEventHandler() {
+        result = this.getAMethod() and
+        result.getName().matches("on_%")
+      }
+    }
+
+    private class NamespaceEventHandler extends Http::Server::RequestHandler::Range {
+      NamespaceEventHandler() { this = any(NamespaceClass nc).getAnEventHandler() }
+
+      override Parameter getARoutedParameter() {
+        result = this.getAnArg() and
+        not result = this.getArg(0) and
+        not result = this.getArg(1) // First 2 parameters are `self` and `sid`.
+      }
+
+      override string getFramework() { result = "socketio" }
+    }
+  }
+}
diff --git a/python/ql/test/library-tests/frameworks/socketio/ConceptsTest.expected b/python/ql/test/library-tests/frameworks/socketio/ConceptsTest.expected
new file mode 100644
index 000000000000..e69de29bb2d1
diff --git a/python/ql/test/library-tests/frameworks/socketio/ConceptsTest.ql b/python/ql/test/library-tests/frameworks/socketio/ConceptsTest.ql
new file mode 100644
index 000000000000..b557a0bccb69
--- /dev/null
+++ b/python/ql/test/library-tests/frameworks/socketio/ConceptsTest.ql
@@ -0,0 +1,2 @@
+import python
+import experimental.meta.ConceptsTest
diff --git a/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.expected b/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.expected
new file mode 100644
index 000000000000..020c338fd192
--- /dev/null
+++ b/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.expected
@@ -0,0 +1,3 @@
+argumentToEnsureNotTaintedNotMarkedAsSpurious
+untaintedArgumentToEnsureTaintedNotMarkedAsMissing
+testFailures
diff --git a/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.ql b/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.ql
new file mode 100644
index 000000000000..8524da5fe7db
--- /dev/null
+++ b/python/ql/test/library-tests/frameworks/socketio/InlineTaintTest.ql
@@ -0,0 +1,2 @@
+import experimental.meta.InlineTaintTest
+import MakeInlineTaintTest<TestTaintTrackingConfig>
diff --git a/python/ql/test/library-tests/frameworks/socketio/taint_test.py b/python/ql/test/library-tests/frameworks/socketio/taint_test.py
new file mode 100644
index 000000000000..07d109aa9a2f
--- /dev/null
+++ b/python/ql/test/library-tests/frameworks/socketio/taint_test.py
@@ -0,0 +1,69 @@
+import sys
+import socketio 
+
+def ensure_tainted(*args):
+    print("tainted", args)
+
+def ensure_not_tainted(*args):
+    print("not tainted", args)
+
+sio = socketio.Server()
+
+@sio.event
+def connect(sid, environ, auth): # $ requestHandler routedParameter=environ routedParameter=auth
+    ensure_not_tainted(sid)
+    ensure_tainted(environ,  # $ tainted
+                   auth)     # $ tainted
+
+@sio.event
+def event1(sid, data): # $ requestHandler routedParameter=data
+    ensure_not_tainted(sid)
+    ensure_tainted(data)  # $ tainted
+    res = sio.call("e1", sid=sid)
+    ensure_tainted(res)  # $ tainted
+    sio.emit("e2", "hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+    sio.send("hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+
+class MyNamespace(socketio.Namespace):
+    def on_event2(self, sid, data):  # $ requestHandler routedParameter=data
+        ensure_not_tainted(self, sid)
+        ensure_tainted(data)  # $ tainted
+        res = self.call("e1", sid=sid) 
+        ensure_tainted(res)  # $ tainted
+        self.emit("e2", "hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+        self.send("hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+
+sio.register_namespace(MyNamespace("/ns"))
+
+asio = socketio.AsyncServer(async_mode='asgi')
+
+@asio.event
+async def event3(sid, data): # $ requestHandler routedParameter=data
+    ensure_not_tainted(sid)
+    ensure_tainted(data)  # $ tainted
+    res = await asio.call("e1", sid=sid)
+    ensure_tainted(res)  # $ tainted
+    await asio.emit("e2", "hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+    await asio.send("hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+
+class MyAsyncNamespace(socketio.AsyncNamespace):
+    async def on_event4(self, sid, data):  # $ requestHandler routedParameter=data
+        ensure_not_tainted(self, sid)
+        ensure_tainted(data)  # $ tainted
+        res = await self.call("e1", sid=sid) 
+        ensure_tainted(res)  # $ tainted
+        await self.emit("e2", "hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+        await self.send("hi", to=sid, callback=lambda x: ensure_tainted(x))   # $ tainted $ requestHandler routedParameter=x
+
+asio.register_namespace(MyAsyncNamespace("/ns"))
+
+if __name__ == "__main__":
+    
+    if "--async" in sys.argv: # $ threatModelSource[commandargs]=sys.argv
+        import uvicorn
+        app = socketio.ASGIApp(asio)
+        uvicorn.run(app, host='127.0.0.1', port=8000)
+    else:
+        import eventlet
+        app = socketio.WSGIApp(sio)
+        eventlet.wsgi.server(eventlet.listen(('', 8000)), app)
\ No newline at end of file
diff --git a/python/ql/test/library-tests/frameworks/socketio/test.py b/python/ql/test/library-tests/frameworks/socketio/test.py
new file mode 100644
index 000000000000..f603edd3111f
--- /dev/null
+++ b/python/ql/test/library-tests/frameworks/socketio/test.py
@@ -0,0 +1,29 @@
+import socketio 
+
+sio = socketio.Server()
+
+@sio.on("connect")
+def connect(sid, environ, auth): # $ requestHandler routedParameter=environ routedParameter=auth
+    print("connect", sid, environ, auth)
+
+@sio.on("event1")
+def handle(sid, data): # $ requestHandler routedParameter=data
+    print("e1", sid, data)
+
+@sio.event
+def event2(sid, data): # $ requestHandler routedParameter=data
+    print("e2", sid, data)
+
+def event3(sid, data): # $ requestHandler routedParameter=data
+    print("e3", sid, data)
+
+sio.on("event3", handler=event3)
+
+sio.on("event4", lambda sid,data: print("e4", sid, data)) # $ requestHandler routedParameter=data
+
+
+
+if __name__ == "__main__":
+    app = socketio.WSGIApp(sio)
+    import eventlet 
+    eventlet.wsgi.server(eventlet.listen(('', 8000)), app)
\ No newline at end of file