diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index 13737068d3..6fd6077b3a 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -58,6 +58,7 @@ Changelog
  * Fix: Show not allowed extension in error message (Sahil Jangra)
  * Fix: Fix focal point chooser when localization enabled (Sébastien Corbin)
  * Fix: Ensure that system checks for `WAGTAIL_DATE_FORMAT`, `WAGTAIL_DATETIME_FORMAT` and `WAGTAIL_TIME_FORMAT` take `FORMAT_MODULE_PATH` into account (Sébastien Corbin)
+ * Fix: Prevent rich text fields inside choosers from being duplicated when opened repeatedly (Sage Abdullah)
  * Docs: Remove duplicate section on frontend caching proxies from performance page (Jake Howard)
  * Docs: Document `restriction_type` field on PageViewRestriction (Shlomo Markowitz)
  * Docs: Document Wagtail's bug bounty policy (Jake Howard)
diff --git a/client/src/entrypoints/admin/draftail.js b/client/src/entrypoints/admin/draftail.js
index 6534c43c7a..950ff8c9f5 100644
--- a/client/src/entrypoints/admin/draftail.js
+++ b/client/src/entrypoints/admin/draftail.js
@@ -11,52 +11,59 @@ import draftail, {
  * Entry point loaded when the Draftail editor is in use.
  */
 
-// Expose Draftail package as a global.
-window.Draftail = Draftail;
-// Expose module as a global.
-window.draftail = draftail;
+// This file is included and run when there's a DraftailRichTextArea widget in the response.
+// Normally this is only included once in the initial page load, but it may be included
+// more than once when there's an AJAX response that includes the widget, e.g. in choosers.
+// Ensure we only run the initialization code once.
+// https://github.com/wagtail/wagtail/issues/12002
+if (!window.Draftail || !window.draftail) {
+  // Expose Draftail package as a global.
+  window.Draftail = Draftail;
+  // Expose module as a global.
+  window.draftail = draftail;
 
-/** @deprecated RemovedInWagtail70 - Ensure that any third party packages that use global.chooserUrls can still append to this global object until support is removed. */
-window.chooserUrls = global.chooserUrls || {};
+  /** @deprecated RemovedInWagtail70 - Ensure that any third party packages that use global.chooserUrls can still append to this global object until support is removed. */
+  window.chooserUrls = global.chooserUrls || {};
 
-// Plugins for the built-in entities.
-const entityTypes = [
-  {
-    type: 'DOCUMENT',
-    source: draftail.DocumentModalWorkflowSource,
-    decorator: Document,
-  },
-  {
-    type: 'LINK',
-    source: draftail.LinkModalWorkflowSource,
-    decorator: Link,
-    onPaste: onPasteLink,
-  },
-  {
-    type: 'IMAGE',
-    source: draftail.ImageModalWorkflowSource,
-    block: ImageBlock,
-  },
-  {
-    type: 'EMBED',
-    source: draftail.EmbedModalWorkflowSource,
-    block: EmbedBlock,
-  },
-];
+  // Plugins for the built-in entities.
+  const entityTypes = [
+    {
+      type: 'DOCUMENT',
+      source: draftail.DocumentModalWorkflowSource,
+      decorator: Document,
+    },
+    {
+      type: 'LINK',
+      source: draftail.LinkModalWorkflowSource,
+      decorator: Link,
+      onPaste: onPasteLink,
+    },
+    {
+      type: 'IMAGE',
+      source: draftail.ImageModalWorkflowSource,
+      block: ImageBlock,
+    },
+    {
+      type: 'EMBED',
+      source: draftail.EmbedModalWorkflowSource,
+      block: EmbedBlock,
+    },
+  ];
 
-entityTypes.forEach((type) => draftail.registerPlugin(type, 'entityTypes'));
+  entityTypes.forEach((type) => draftail.registerPlugin(type, 'entityTypes'));
 
-/**
- * Initialize a Draftail editor on a given element when the w-draftail:init event is fired.
- */
-document.addEventListener('w-draftail:init', ({ detail = {}, target }) => {
-  const id = target.id;
+  /**
+   * Initialize a Draftail editor on a given element when the w-draftail:init event is fired.
+   */
+  document.addEventListener('w-draftail:init', ({ detail = {}, target }) => {
+    const id = target.id;
 
-  if (!id) {
-    // eslint-disable-next-line no-console
-    console.error('`w-draftail:init` event must have a target with an id.');
-    return;
-  }
+    if (!id) {
+      // eslint-disable-next-line no-console
+      console.error('`w-draftail:init` event must have a target with an id.');
+      return;
+    }
 
-  window.draftail.initEditor(`#${id}`, detail, document.currentScript);
-});
+    window.draftail.initEditor(`#${id}`, detail, document.currentScript);
+  });
+}
diff --git a/client/src/entrypoints/admin/draftail.test.js b/client/src/entrypoints/admin/draftail.test.js
index 2484e85740..5a22615f9d 100644
--- a/client/src/entrypoints/admin/draftail.test.js
+++ b/client/src/entrypoints/admin/draftail.test.js
@@ -62,7 +62,7 @@ describe('Calling initEditor via event dispatching', () => {
     jest.resetAllMocks();
   });
 
-  it.only('should support creating a new editor with event dispatching', async () => {
+  it('should support creating a new editor with event dispatching', async () => {
     expect(window.draftail.initEditor).not.toHaveBeenCalled();
 
     document.body.innerHTML = '<main><input id="editor"></main>';
@@ -106,6 +106,59 @@ describe('Calling initEditor via event dispatching', () => {
   afterAll(() => {
     console.error.mockRestore();
     window.draftail.initEditor.mockRestore();
-    /* eslint-enable no-console */
+  });
+});
+
+describe('importing the module multiple times', () => {
+  it('should run the init function once if the script is included multiple times', async () => {
+    // Imported at the top level (similar to the initial page load)
+    const firstDraftail = window.draftail;
+
+    // Subsequent imports (e.g. in AJAX responses)
+    jest.isolateModules(() => {
+      require('./draftail');
+    });
+
+    // Should be the same instance
+    const secondDraftail = window.draftail;
+    expect(secondDraftail).toBe(firstDraftail);
+
+    jest.isolateModules(() => {
+      require('./draftail');
+    });
+
+    const thirdDraftail = window.draftail;
+    expect(thirdDraftail).toBe(firstDraftail);
+
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+    jest.spyOn(window.draftail, 'initEditor').mockImplementation(() => {});
+
+    expect(window.draftail.initEditor).not.toHaveBeenCalled();
+
+    document.body.innerHTML = '<main><input id="editor"></main>';
+
+    document.getElementById('editor').dispatchEvent(
+      new CustomEvent('w-draftail:init', {
+        bubbles: true,
+        cancelable: false,
+        detail: { some: 'detail' },
+      }),
+    );
+
+    expect(console.error).toHaveBeenCalledTimes(0);
+
+    // Should only be called once. If the script isn't written correctly, then
+    // the window.draftail object would be a new instance every time, or
+    // the initEditor function would be called multiple times.
+    expect(window.draftail.initEditor).toHaveBeenCalledTimes(1);
+    expect(window.draftail.initEditor).toHaveBeenLastCalledWith(
+      '#editor',
+      { some: 'detail' },
+      null,
+    );
+
+    /* eslint-enable no-console */
+    jest.clearAllMocks();
+    jest.restoreAllMocks();
   });
 });
diff --git a/docs/releases/6.2.md b/docs/releases/6.2.md
index bc2d93d6d3..791137f115 100644
--- a/docs/releases/6.2.md
+++ b/docs/releases/6.2.md
@@ -85,6 +85,7 @@ StreamField definitions within migrations are now represented in a more compact
  * Show not allowed extension in error message (Sahil Jangra)
  * Fix focal point chooser when localization enabled (Sébastien Corbin)
  * Ensure that system checks for `WAGTAIL_DATE_FORMAT`, `WAGTAIL_DATETIME_FORMAT` and `WAGTAIL_TIME_FORMAT` take `FORMAT_MODULE_PATH` into account (Sébastien Corbin)
+ * Prevent rich text fields inside choosers from being duplicated when opened repeatedly (Sage Abdullah)
 
 ### Documentation