diff --git a/doc/api/worker_threads.md b/doc/api/worker_threads.md
index 525825ade82621..a353b25ccce595 100644
--- a/doc/api/worker_threads.md
+++ b/doc/api/worker_threads.md
@@ -995,6 +995,66 @@ added: v15.4.0
 
 * `message` {any} Any cloneable JavaScript value.
 
+### `messageEvent.sender`
+
+<!-- YAML added: REPLACEME -->
+
+> Stability: 1 - Experimental
+
+Type: {number}
+
+A Node.js-specific extension that identifies the sender of a
+BroadcastChannel message.
+
+When a message originates, sender is the threadId of the
+worker that posted the message.
+
+```mjs
+import {
+  isMainThread,
+  BroadcastChannel,
+  Worker,
+} from 'node:worker_threads';
+
+const bc = new BroadcastChannel('hello');
+
+if (isMainThread) {
+  let c = 0;
+  bc.onmessage = ({ data, sender }) => {
+    console.log(`Received "${data}" from worker ${sender}`);
+    if (++c === 10) bc.close();
+  };
+  for (let n = 0; n < 10; n++)
+    new Worker(new URL(import.meta.url));
+} else {
+  bc.postMessage('hello from every worker');
+  bc.close();
+}
+```
+
+```cjs
+const {
+  isMainThread,
+  BroadcastChannel,
+  Worker,
+} = require('node:worker_threads');
+
+const bc = new BroadcastChannel('hello');
+
+if (isMainThread) {
+  let c = 0;
+  bc.onmessage = ({ data, sender }) => {
+    console.log(`Received "${data}" from worker ${sender}`);
+    if (++c === 10) bc.close();
+  };
+  for (let n = 0; n < 10; n++)
+    new Worker(__filename);
+} else {
+  bc.postMessage('hello from every worker');
+  bc.close();
+}
+```
+
 ### `broadcastChannel.ref()`
 
 <!-- YAML
diff --git a/lib/internal/worker/io.js b/lib/internal/worker/io.js
index 786ee36c1927fa..a4d05194573060 100644
--- a/lib/internal/worker/io.js
+++ b/lib/internal/worker/io.js
@@ -48,6 +48,7 @@ const {
 } = internalBinding('messaging');
 const {
   getEnvMessagePort,
+  threadId,
 } = internalBinding('worker');
 
 const { Readable, Writable } = require('stream');
@@ -346,7 +347,15 @@ function receiveMessageOnPort(port) {
 }
 
 function onMessageEvent(type, data) {
-  this.dispatchEvent(lazyMessageEvent(type, { data }));
+  const event = lazyMessageEvent(type, { data: data.value });
+  ObjectDefineProperty(event, 'sender', {
+    __proto__: null,
+    value: data.sender,
+    enumerable: false,
+    writable: false,
+    configurable: false,
+  });
+  this.dispatchEvent(event);
 }
 
 function isBroadcastChannel(value) {
@@ -419,13 +428,17 @@ class BroadcastChannel extends EventTarget {
    * @returns {void}
    */
   postMessage(message) {
+    const broadcastMessage = {
+      sender: threadId,
+      value: message,
+    };
     if (!isBroadcastChannel(this))
       throw new ERR_INVALID_THIS('BroadcastChannel');
     if (arguments.length === 0)
       throw new ERR_MISSING_ARGS('message');
     if (this[kHandle] === undefined)
       throw new DOMException('BroadcastChannel is closed.', 'InvalidStateError');
-    if (this[kHandle].postMessage(message) === undefined)
+    if (this[kHandle].postMessage(broadcastMessage) === undefined)
       throw new DOMException('Message could not be posted.');
   }
 
diff --git a/test/parallel/test-worker-broadcastchannel.js b/test/parallel/test-worker-broadcastchannel.js
index 12535271c15596..49fa49af71aadf 100644
--- a/test/parallel/test-worker-broadcastchannel.js
+++ b/test/parallel/test-worker-broadcastchannel.js
@@ -147,7 +147,7 @@ assert.throws(() => new BroadcastChannel(), {
   const bc1 = new BroadcastChannel('channel4');
   const bc2 = new BroadcastChannel('channel4');
   bc1.postMessage('some data');
-  assert.strictEqual(receiveMessageOnPort(bc2).message, 'some data');
+  assert.strictEqual(receiveMessageOnPort(bc2).message.value, 'some data');
   assert.strictEqual(receiveMessageOnPort(bc2), undefined);
   bc1.close();
   bc2.close();
@@ -183,3 +183,32 @@ assert.throws(() => new BroadcastChannel(), {
     "BroadcastChannel { name: 'channel5', active: false }"
   );
 }
+
+{
+  const bc = new BroadcastChannel('worker-source');
+
+  new Worker(`
+    const assert = require('assert');
+    const { BroadcastChannel, threadId } = require('worker_threads');
+
+    const bc = new BroadcastChannel('worker-source');
+
+    bc.onmessage = (evt) => {
+      assert.strictEqual(evt.data, 'from-main');
+      assert.strictEqual(evt.sender, 0);
+
+      bc.close();
+    };
+
+    bc.postMessage('from-worker');
+  `, { eval: true });
+
+  bc.onmessage = common.mustCall((evt) => {
+    assert.strictEqual(evt.data, 'from-worker');
+
+    assert.ok(evt.sender > 0);
+
+    bc.postMessage('from-main');
+    bc.close();
+  });
+}