diff --git a/app/scripts/lib/createMainFrameOriginMiddleware.ts b/app/scripts/lib/createMainFrameOriginMiddleware.ts
new file mode 100644
index 000000000000..bcbc2cb7d6fd
--- /dev/null
+++ b/app/scripts/lib/createMainFrameOriginMiddleware.ts
@@ -0,0 +1,24 @@
+// Request and responses are currently untyped.
+/* eslint-disable @typescript-eslint/no-explicit-any */
+
+/**
+ * Returns a middleware that appends the mainFrameOrigin to request
+ *
+ * @param {{ mainFrameOrigin: string }} opts - The middleware options
+ * @returns {Function}
+ */
+
+export default function createMainFrameOriginMiddleware({
+  mainFrameOrigin,
+}: {
+  mainFrameOrigin: string;
+}) {
+  return function mainFrameOriginMiddleware(
+    req: any,
+    _res: any,
+    next: () => void,
+  ) {
+    req.mainFrameOrigin = mainFrameOrigin;
+    next();
+  };
+}
diff --git a/app/scripts/metamask-controller.js b/app/scripts/metamask-controller.js
index 41687031aec5..3d73379dfc93 100644
--- a/app/scripts/metamask-controller.js
+++ b/app/scripts/metamask-controller.js
@@ -296,6 +296,7 @@ import {
   createUnsupportedMethodMiddleware,
 } from './lib/rpc-method-middleware';
 import createOriginMiddleware from './lib/createOriginMiddleware';
+import createMainFrameOriginMiddleware from './lib/createMainFrameOriginMiddleware';
 import createTabIdMiddleware from './lib/createTabIdMiddleware';
 import { NetworkOrderController } from './controllers/network-order';
 import { AccountOrderController } from './controllers/account-order';
@@ -5669,11 +5670,18 @@ export default class MetamaskController extends EventEmitter {
       tabId = sender.tab.id;
     }
 
+    let mainFrameOrigin = origin;
+    if (sender.tab && sender.tab.url) {
+      // If sender origin is an iframe, then get the top-level frame's origin
+      mainFrameOrigin = new URL(sender.tab.url).origin;
+    }
+
     const engine = this.setupProviderEngineEip1193({
       origin,
       sender,
       subjectType,
       tabId,
+      mainFrameOrigin,
     });
 
     const dupeReqFilterStream = createDupeReqFilterStream();
@@ -5794,13 +5802,25 @@ export default class MetamaskController extends EventEmitter {
    * @param {MessageSender | SnapSender} options.sender - The sender object.
    * @param {string} options.subjectType - The type of the sender subject.
    * @param {tabId} [options.tabId] - The tab ID of the sender - if the sender is within a tab
+   * @param {mainFrameOrigin} [options.mainFrameOrigin] - The origin of the main frame if the sender is an iframe
    */
-  setupProviderEngineEip1193({ origin, subjectType, sender, tabId }) {
+  setupProviderEngineEip1193({
+    origin,
+    subjectType,
+    sender,
+    tabId,
+    mainFrameOrigin,
+  }) {
     const engine = new JsonRpcEngine();
 
     // Append origin to each request
     engine.push(createOriginMiddleware({ origin }));
 
+    // Append mainFrameOrigin to each request if present
+    if (mainFrameOrigin) {
+      engine.push(createMainFrameOriginMiddleware({ mainFrameOrigin }));
+    }
+
     // Append selectedNetworkClientId to each request
     engine.push(createSelectedNetworkMiddleware(this.controllerMessenger));