diff --git a/.changeset/many-houses-occur.md b/.changeset/many-houses-occur.md
new file mode 100644
index 0000000000..b9da4b217c
--- /dev/null
+++ b/.changeset/many-houses-occur.md
@@ -0,0 +1,5 @@
+---
+"@tiptap/core": minor
+---
+
+Add configurable tabindex option to allow customizing the tabindex attribute on the editor element via coreExtensionOptions
diff --git a/packages/core/__tests__/tabindex.spec.ts b/packages/core/__tests__/tabindex.spec.ts
new file mode 100644
index 0000000000..39bfe674c9
--- /dev/null
+++ b/packages/core/__tests__/tabindex.spec.ts
@@ -0,0 +1,74 @@
+import { Editor } from '@tiptap/core'
+import Document from '@tiptap/extension-document'
+import Paragraph from '@tiptap/extension-paragraph'
+import Text from '@tiptap/extension-text'
+import { describe, expect, it } from 'vitest'
+
+describe('tabindex extension', () => {
+  it('should set tabindex="0" on editable editor by default', () => {
+    const editor = new Editor({
+      extensions: [Document, Paragraph, Text],
+    })
+
+    expect(editor.view.dom.getAttribute('tabindex')).toBe('0')
+
+    editor.destroy()
+  })
+
+  it('should not set tabindex on non-editable editor by default', () => {
+    const editor = new Editor({
+      extensions: [Document, Paragraph, Text],
+      editable: false,
+    })
+
+    expect(editor.view.dom.getAttribute('tabindex')).toBeNull()
+
+    editor.destroy()
+  })
+
+  it('should set custom tabindex on editable editor when configured', () => {
+    const editor = new Editor({
+      extensions: [Document, Paragraph, Text],
+      coreExtensionOptions: {
+        tabindex: {
+          value: '4',
+        },
+      },
+    })
+
+    expect(editor.view.dom.getAttribute('tabindex')).toBe('4')
+
+    editor.destroy()
+  })
+
+  it('should set custom tabindex on non-editable editor when configured', () => {
+    const editor = new Editor({
+      extensions: [Document, Paragraph, Text],
+      editable: false,
+      coreExtensionOptions: {
+        tabindex: {
+          value: '-1',
+        },
+      },
+    })
+
+    expect(editor.view.dom.getAttribute('tabindex')).toBe('-1')
+
+    editor.destroy()
+  })
+
+  it('should set tabindex="0" when value is explicitly undefined', () => {
+    const editor = new Editor({
+      extensions: [Document, Paragraph, Text],
+      coreExtensionOptions: {
+        tabindex: {
+          value: undefined,
+        },
+      },
+    })
+
+    expect(editor.view.dom.getAttribute('tabindex')).toBe('0')
+
+    editor.destroy()
+  })
+})
diff --git a/packages/core/src/Editor.ts b/packages/core/src/Editor.ts
index c9f83e641b..415c034d20 100644
--- a/packages/core/src/Editor.ts
+++ b/packages/core/src/Editor.ts
@@ -433,7 +433,9 @@ export class Editor extends EventEmitter<EditorEvents> {
           Commands,
           FocusEvents,
           Keymap,
-          Tabindex,
+          Tabindex.configure({
+            value: this.options.coreExtensionOptions?.tabindex?.value,
+          }),
           Drop,
           Paste,
           Delete,
diff --git a/packages/core/src/extensions/tabindex.ts b/packages/core/src/extensions/tabindex.ts
index da14d02afe..aa886c8be2 100644
--- a/packages/core/src/extensions/tabindex.ts
+++ b/packages/core/src/extensions/tabindex.ts
@@ -2,15 +2,55 @@ import { Plugin, PluginKey } from '@tiptap/pm/state'
 
 import { Extension } from '../Extension.js'
 
-export const Tabindex = Extension.create({
+/**
+ * Options for the Tabindex extension.
+ */
+export type TabindexOptions = {
+  /**
+   * The value for the `tabindex` attribute on the editor element.
+   * When undefined, editable editors default to `0` and non-editable editors get no tabindex.
+   */
+  value?: string
+}
+
+/**
+ * The Tabindex extension adds a configurable tabindex attribute to the editor.
+ *
+ * By default, the editor gets tabindex="0" when editable. This can be customized
+ * via coreExtensionOptions to support specific focus ordering requirements in forms
+ * or to enable focusing on non-editable editors.
+ *
+ * @example
+ * ```ts
+ * new Editor({
+ *   coreExtensionOptions: {
+ *     tabindex: {
+ *       value: '-1',
+ *     },
+ *   },
+ * })
+ * ```
+ */
+export const Tabindex = Extension.create<TabindexOptions>({
   name: 'tabindex',
 
+  addOptions() {
+    return {
+      value: undefined,
+    }
+  },
+
   addProseMirrorPlugins() {
     return [
       new Plugin({
         key: new PluginKey('tabindex'),
         props: {
-          attributes: (): { [name: string]: string } => (this.editor.isEditable ? { tabindex: '0' } : {}),
+          attributes: (): { [name: string]: string } => {
+            if (!this.editor.isEditable && this.options.value === undefined) {
+              return {}
+            }
+            return { tabindex: this.options.value ?? '0' }
+          },
         },
       }),
     ]
diff --git a/packages/core/src/types.ts b/packages/core/src/types.ts
index f8046174f1..de1bd45b99 100644
--- a/packages/core/src/types.ts
+++ b/packages/core/src/types.ts
@@ -339,6 +339,15 @@ export interface EditorOptions {
     clipboardTextSerializer?: {
       blockSeparator?: string
     }
+    /**
+     * Options for the `tabindex` core extension.
+     */
+    tabindex?: {
+      /**
+       * The value for the `tabindex` attribute on the editor element.
+       */
+      value?: string
+    }
     delete?: {
       /**
        * Whether the `delete` extension should be called asynchronously to avoid blocking the editor while processing deletions