diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8ab86c134..1b3f2d801 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,8 +8,13 @@ on:
 
 jobs:
   build:
-    name: Browser tests
+    name: "Browser tests (ElementInternals: ${{ matrix.elementInternals }})"
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        elementInternals: [false, true]
+    env:
+      EDITOR_ELEMENT_INTERNALS: "${{ matrix.elementInternals }}"
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
diff --git a/README.md b/README.md
index 9a1cfe6e7..28a5c7ed4 100644
--- a/README.md
+++ b/README.md
@@ -19,7 +19,7 @@ This is the approach that all modern, production ready, WYSIWYG editors now take
 
 <details><summary>Trix supports all evergreen, self-updating desktop and mobile browsers.</summary><img src="https://app.saucelabs.com/browser-matrix/basecamp_trix.svg"></details>
 
-Trix is built with established web standards, notably [Custom Elements](https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements), [Mutation Observer](https://dom.spec.whatwg.org/#mutation-observers), and [Promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise).
+Trix is built with established web standards, notably [Custom Elements](https://developer.mozilla.org/en-US/docs/Web/Web_Components/Using_custom_elements), [Element Internals](https://developer.mozilla.org/en-US/docs/Web/API/ElementInternals), [Mutation Observer](https://dom.spec.whatwg.org/#mutation-observers), and [Promises](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise).
 
 # Getting Started
 
@@ -49,12 +49,26 @@ document.addEventListener("trix-before-initialize", () => {
 
 ## Creating an Editor
 
-Place an empty `<trix-editor></trix-editor>` tag on the page. Trix will automatically insert a separate `<trix-toolbar>` before the editor.
+Place an empty `<trix-editor></trix-editor>` tag on the page. If the `<trix-editor>` element is rendered with a `[toolbar]` attribute that references the element by its `[id]`, it will treat that element as its toolbar:
+
+```html
+<trix-toolbar id="editor_toolbar"></trix-toolbar>
+
+<trix-editor toolbar="editor_toolbar"></trix-editor>
+```
+
+Otherwise, Trix will automatically insert a separate `<trix-toolbar>` before the editor.
 
 Like an HTML `<textarea>`, `<trix-editor>` accepts `autofocus` and `placeholder` attributes. Unlike a `<textarea>`, `<trix-editor>` automatically expands vertically to fit its contents.
 
 ## Integrating With Forms
 
+There are two styles of integrating with `<form>` element submissions.
+
+### Legacy integration with `<input type="hidden">`
+
+Legacy support is provided through an `<input type="hidden">` element paired with an `[input]` attribute on the `<trix-editor>` element.
+
 To submit the contents of a `<trix-editor>` with a form, first define a hidden input field in the form and assign it an `id`. Then reference that `id` in the editor’s `input` attribute.
 
 ```html
@@ -66,7 +80,7 @@ To submit the contents of a `<trix-editor>` with a form, first define a hidden i
 
 Trix will automatically update the value of the hidden input field with each change to the editor.
 
-## Populating With Stored Content
+#### Populating With Stored Content
 
 To populate a `<trix-editor>` with stored content, include that content in the associated input element’s `value` attribute.
 
@@ -79,6 +93,44 @@ To populate a `<trix-editor>` with stored content, include that content in the a
 
 Always use an associated input element to safely populate an editor. Trix won’t load any HTML content inside a `<trix-editor>…</trix-editor>` tag.
 
+### Integration with Element Internals
+
+Trix can also be configured to integrate with forms through the `<trix-editor>` element's `ElementInternals` instance.
+
+First, configure Trix to opt-into its Element Internals support by rendering a `<meta>` element into the document's `<head>`:
+
+```html
+<head>
+  <!-- … -->
+  <meta name="trix-editor-formAssociated" content="true">
+</head>
+```
+
+Then, to submit the contents of a `<trix-editor>` with a `<form>`, render the element with a `[name]` attribute and its initial value as its inner HTML.
+
+```html
+<form …>
+  <trix-editor name="content"></trix-editor>
+</form>
+```
+
+To associate the element with a `<form>` that isn't an ancestor, render the element with a `[form]` attribute that references the `<form>` element by its `[id]`:
+
+```html
+<form id="a-form-element" …></form>
+<trix-editor name="content" form="a-form-element"></trix-editor>
+```
+
+#### Populating With Stored Content
+
+To populate a `<trix-editor>` with stored content, include that content as HTML inside the element’s inner HTML.
+
+```html
+<form …>
+  <trix-editor>Editor content goes here</trix-editor>
+</form>
+```
+
 ## Providing an Accessible Name
 
 Like other form controls, `<trix-editor>` elements should have an accessible name. The `<trix-editor>` element integrates with `<label>` elements and The `<trix-editor>` supports two styles of integrating with `<label>` elements:
diff --git a/assets/index.html b/assets/index.html
index 9ddebeab1..32b4ece11 100644
--- a/assets/index.html
+++ b/assets/index.html
@@ -12,7 +12,7 @@
         box-sizing: border-box;
       }
 
-      main {
+      main, nav {
         margin: 20px auto;
         max-width: 700px;
       }
@@ -69,8 +69,27 @@
         }
       });
     </script>
+    <script>
+      const searchParams = new URLSearchParams(location.search)
+
+      if (searchParams.get("editor") === "formAssociated") {
+        document.head.insertAdjacentHTML(
+          "beforeend",
+          `<meta name="trix-editor-formAssociated" content="true">`
+        )
+
+        document.addEventListener("trix-change", function(event) {
+          var input = document.getElementById("input")
+          input.value = event.target.value
+        })
+      }
+    </script>
   </head>
   <body>
+    <nav>
+      <a href="/">Legacy support</a>
+      <a href="/?editor=formAssociated">ElementInternals support</a>
+    </nav>
     <main>
       <label for="editor">Input</label>
       <trix-editor autofocus class="trix-content" input="input" id="editor"></trix-editor>
diff --git a/karma.conf.js b/karma.conf.js
index 725a68dcf..601597e29 100644
--- a/karma.conf.js
+++ b/karma.conf.js
@@ -101,6 +101,10 @@ if (process.env.SAUCE_ACCESS_KEY) {
   }
 }
 
+if (process.env.EDITOR_ELEMENT_INTERNALS === "true") {
+  config.files.unshift({ pattern: "src/test/test_helpers/fixtures/element_internals.js", watched: false, included: true })
+}
+
 function buildId() {
   const { GITHUB_WORKFLOW, GITHUB_RUN_NUMBER, GITHUB_RUN_ID } = process.env
   return GITHUB_WORKFLOW && GITHUB_RUN_NUMBER && GITHUB_RUN_ID
diff --git a/src/test/system/accessibility_test.js b/src/test/system/accessibility_test.js
index a86a61767..ea734aa25 100644
--- a/src/test/system/accessibility_test.js
+++ b/src/test/system/accessibility_test.js
@@ -1,4 +1,5 @@
-import { assert, test, testGroup, triggerEvent } from "test/test_helper"
+import * as config from "trix/config"
+import { assert, test, testGroup, testIf, testUnless, triggerEvent } from "test/test_helper"
 
 testGroup("Accessibility attributes", { template: "editor_default_aria_label" }, () => {
   test("sets the role to textbox", () => {
@@ -22,12 +23,12 @@ testGroup("Accessibility attributes", { template: "editor_default_aria_label" },
     assert.equal(editor.getAttribute("aria-labelledby"), "aria-labelledby-id")
   })
 
-  test("assigns aria-label to the text of the element's <label> elements", () => {
+  testUnless(config.editor.formAssociated, "assigns aria-label to the text of the element's <label> elements", () => {
     const editor = document.getElementById("editor-with-labels")
     assert.equal(editor.getAttribute("aria-label"), "Label 1 Label 2 Label 3")
   })
 
-  test("updates the aria-label on focus", () => {
+  testUnless(config.editor.formAssociated, "updates the aria-label on focus", () => {
     const editor = document.getElementById("editor-with-modified-label")
     const label = document.getElementById("modified-label")
 
@@ -35,4 +36,13 @@ testGroup("Accessibility attributes", { template: "editor_default_aria_label" },
     triggerEvent(editor, "focus")
     assert.equal(editor.getAttribute("aria-label"), "New Value")
   })
+
+  testIf(config.editor.formAssociated, "does not set [aria-label] for a <label> element", () => {
+    const editor = document.getElementById("editor-with-labels")
+    const labels = Array.from(editor.labels)
+    const text = labels.map((label) => label.textContent.trim())
+
+    assert.deepEqual(text, [ "Label 1", "Label 2", "Label 3" ])
+    assert.equal(editor.getAttribute("aria-label"), null)
+  })
 })
diff --git a/src/test/system/custom_element_test.js b/src/test/system/custom_element_test.js
index 81de91c5a..1da42a246 100644
--- a/src/test/system/custom_element_test.js
+++ b/src/test/system/custom_element_test.js
@@ -1,3 +1,4 @@
+import * as config from "trix/config"
 import { rangesAreEqual } from "trix/core/helpers"
 
 import {
@@ -13,6 +14,7 @@ import {
   test,
   testGroup,
   testIf,
+  testUnless,
   triggerEvent,
   typeCharacters,
   typeInToolbarDialog,
@@ -510,12 +512,12 @@ testGroup("<label> support", { template: "editor_with_labels" }, () => {
     assert.deepEqual(Array.from(getEditorElement().labels), labels)
   })
 
-  test("focuses when <label> clicked", () => {
+  testUnless(config.editor.formAssociated, "focuses when <label> clicked", () => {
     document.getElementById("label-1").click()
     assert.equal(getEditorElement(), document.activeElement)
   })
 
-  test("focuses when <label> descendant clicked", () => {
+  testUnless(config.editor.formAssociated, "focuses when <label> descendant clicked", () => {
     document.getElementById("label-1").querySelector("span").click()
     assert.equal(getEditorElement(), document.activeElement)
   })
diff --git a/src/test/system/installation_process_test.js b/src/test/system/installation_process_test.js
index f484cf5b7..38bd4fb92 100644
--- a/src/test/system/installation_process_test.js
+++ b/src/test/system/installation_process_test.js
@@ -1,6 +1,7 @@
+import * as config from "trix/config"
 import EditorController from "trix/controllers/editor_controller"
 
-import { assert, test, testGroup } from "test/test_helper"
+import { assert, test, testGroup, testUnless } from "test/test_helper"
 import { nextFrame } from "../test_helpers/timing_helpers"
 
 testGroup("Installation process", { template: "editor_html" }, () => {
@@ -31,7 +32,7 @@ testGroup("Installation process without specified elements", { template: "editor
     assert.equal(editorElement.toolbarElement, toolbarElement)
   })
 
-  test("creates identified input elements", () => {
+  testUnless(config.editor.formAssociated, "creates identified input elements", () => {
     const editorElement = getEditorElement()
 
     const inputId = editorElement.getAttribute("input")
diff --git a/src/test/test_helpers/fixtures/editor_html.js b/src/test/test_helpers/fixtures/editor_html.js
index 6726380b2..3dc667395 100644
--- a/src/test/test_helpers/fixtures/editor_html.js
+++ b/src/test/test_helpers/fixtures/editor_html.js
@@ -1,3 +1,8 @@
+import * as config from "trix/config"
+
 export default () =>
-  `<input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;">
-  <trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>`
+  config.editor.formAssociated ?
+    `<trix-editor autofocus placeholder="Say hello..."><div>Hello world</div></trix-editor>
+    ` :
+    `<input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;">
+    <trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>`
diff --git a/src/test/test_helpers/fixtures/editor_with_image.js b/src/test/test_helpers/fixtures/editor_with_image.js
index 43bebff24..820bbe0f8 100644
--- a/src/test/test_helpers/fixtures/editor_with_image.js
+++ b/src/test/test_helpers/fixtures/editor_with_image.js
@@ -1,5 +1,9 @@
+import * as config from "trix/config"
 import { TEST_IMAGE_URL } from "./test_image_url"
 
 export default () =>
-  `<trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>
-  <input id="my_input" type="hidden" value="ab&lt;img src=&quot;${TEST_IMAGE_URL}&quot; width=&quot;10&quot; height=&quot;10&quot;&gt;">`
+  config.editor.formAssociated ?
+    `<trix-editor autofocus placeholder="Say hello...">ab<img src="${TEST_IMAGE_URL}" width="10" height="10"></trix-editor>
+    ` :
+    `<trix-editor input="my_input" autofocus placeholder="Say hello..."></trix-editor>
+    <input id="my_input" type="hidden" value="ab&lt;img src=&quot;${TEST_IMAGE_URL}&quot; width=&quot;10&quot; height=&quot;10&quot;&gt;">`
diff --git a/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js b/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js
index 2268e1544..802e5b50e 100644
--- a/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js
+++ b/src/test/test_helpers/fixtures/editor_with_toolbar_and_input.js
@@ -1,6 +1,14 @@
+import * as config from "trix/config"
+
 export default () =>
-  `<ul id="my_editor">
-    <li><trix-toolbar id="my_toolbar"></trix-toolbar></li>
-    <li><trix-editor toolbar="my_toolbar" input="my_input" autofocus placeholder="Say hello..."></trix-editor></li>
-    <li><input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;"></li>
-  </ul>`
+  config.editor.formAssociated ?
+    `<ul id="my_editor">
+      <li><trix-toolbar id="my_toolbar"></trix-toolbar></li>
+      <li><trix-editor toolbar="my_toolbar" autofocus placeholder="Say hello..."><div>Hello world</div></trix-editor></li>
+    </ul>
+    ` :
+    `<ul id="my_editor">
+      <li><trix-toolbar id="my_toolbar"></trix-toolbar></li>
+      <li><trix-editor toolbar="my_toolbar" input="my_input" autofocus placeholder="Say hello..."></trix-editor></li>
+      <li><input id="my_input" type="hidden" value="&lt;div&gt;Hello world&lt;/div&gt;"></li>
+    </ul>`
diff --git a/src/test/test_helpers/fixtures/editors_with_forms.js b/src/test/test_helpers/fixtures/editors_with_forms.js
index 56ed494ac..5e090da84 100644
--- a/src/test/test_helpers/fixtures/editors_with_forms.js
+++ b/src/test/test_helpers/fixtures/editors_with_forms.js
@@ -1,11 +1,21 @@
+import * as config from "trix/config"
+
 export default () =>
-  `<form id="ancestor-form">
-    <trix-editor id="editor-with-ancestor-form"></trix-editor>
-  </form>
+  config.editor.formAssociated ?
+    `<form id="ancestor-form">
+      <trix-editor id="editor-with-ancestor-form"></trix-editor>
+    </form>
+    <form id="input-form"></form>
+    <trix-editor id="editor-with-input-form" form="input-form"></trix-editor>
+    <trix-editor id="editor-with-no-form"></trix-editor>
+    ` :
+    `<form id="ancestor-form">
+      <trix-editor id="editor-with-ancestor-form"></trix-editor>
+    </form>
 
-  <form id="input-form">
-    <input type="hidden" id="hidden-input">
-  </form>
-  <trix-editor id="editor-with-input-form" input="hidden-input"></trix-editor>
+    <form id="input-form">
+      <input type="hidden" id="hidden-input">
+    </form>
+    <trix-editor id="editor-with-input-form" input="hidden-input"></trix-editor>
 
-  <trix-editor id="editor-with-no-form"></trix-editor>`
+    <trix-editor id="editor-with-no-form"></trix-editor>`
diff --git a/src/test/test_helpers/fixtures/element_internals.js b/src/test/test_helpers/fixtures/element_internals.js
new file mode 100644
index 000000000..e47f0bd7c
--- /dev/null
+++ b/src/test/test_helpers/fixtures/element_internals.js
@@ -0,0 +1,4 @@
+document.head.insertAdjacentHTML(
+  "beforeend",
+  `<meta name="trix-editor-formAssociated" content="true">
+`)
diff --git a/src/test/test_helpers/test_helpers.js b/src/test/test_helpers/test_helpers.js
index 96a2bd31c..4ed539dd8 100644
--- a/src/test/test_helpers/test_helpers.js
+++ b/src/test/test_helpers/test_helpers.js
@@ -56,6 +56,10 @@ export const testIf = function (condition, ...args) {
   }
 }
 
+export const testUnless = function(condition, ...args) {
+  testIf(!condition, ...args)
+}
+
 export const { skip, test } = QUnit
 
 const waitForTrixInit = async () => {
diff --git a/src/trix/config/editor.js b/src/trix/config/editor.js
new file mode 100644
index 000000000..026e9eb38
--- /dev/null
+++ b/src/trix/config/editor.js
@@ -0,0 +1,5 @@
+const config = {
+  formAssociated: false
+}
+
+export default config
diff --git a/src/trix/config/index.js b/src/trix/config/index.js
index 27f7abc2f..64684bc1e 100644
--- a/src/trix/config/index.js
+++ b/src/trix/config/index.js
@@ -2,6 +2,7 @@ export { default as attachments } from "./attachments"
 export { default as blockAttributes } from "./block_attributes"
 export { default as browser } from "./browser"
 export { default as css } from "./css"
+export { default as editor } from "./editor"
 export { default as fileSize } from "./file_size_formatting"
 export { default as input } from "./input"
 export { default as keyNames } from "./key_names"
diff --git a/src/trix/elements/trix_editor_element.js b/src/trix/elements/trix_editor_element.js
index 1c6a4b5b6..16e8e3edc 100644
--- a/src/trix/elements/trix_editor_element.js
+++ b/src/trix/elements/trix_editor_element.js
@@ -212,7 +212,7 @@ class InputElementDelegate {
   }
 
   get defaultValue() {
-    return this.value
+    return this.#element.value
   }
 
   // Element lifecycle
@@ -255,6 +255,58 @@ class InputElementDelegate {
   }
 }
 
+class ElementInternalsDelegate {
+  #element
+  #internals
+  #value = ""
+
+  constructor(element) {
+    this.#element = element
+    this.#internals = element.attachInternals()
+  }
+
+  get value() {
+    return this.#value
+  }
+
+  // Properties
+
+  get labels() {
+    return this.#internals.labels
+  }
+
+  get form() {
+    return this.#internals.form
+  }
+
+  get name() {
+    return this.#element.getAttribute("name")
+  }
+
+  get inputElement() {
+    return null
+  }
+
+  get defaultValue() {
+    return this.#element.innerHTML
+  }
+
+  // Form support
+
+  setFormValue(value) {
+    this.#value = value
+    this.#internals.setFormValue(value)
+  }
+
+  // Element lifecycle
+
+  connectedCallback() {
+  }
+
+  disconnectedCallback() {
+  }
+}
+
 export default class TrixEditorElement extends HTMLElement {
   static formAssociated = false
 
@@ -262,7 +314,9 @@ export default class TrixEditorElement extends HTMLElement {
 
   constructor() {
     super()
-    this.#delegate = new InputElementDelegate(this)
+    this.#delegate = this.constructor.formAssociated ?
+      new ElementInternalsDelegate(this) :
+      new InputElementDelegate(this)
   }
 
   // Properties
diff --git a/src/trix/trix.js b/src/trix/trix.js
index b778149ed..f2ac0484c 100644
--- a/src/trix/trix.js
+++ b/src/trix/trix.js
@@ -26,6 +26,14 @@ const Trix = {
 // Expose models under the Trix constant for compatibility with v1
 Object.assign(Trix, models)
 
+for (const element of document.getElementsByName("trix-editor-formAssociated")) {
+  if (element instanceof HTMLMetaElement) {
+    config.editor.formAssociated = element.content === "true"
+  }
+}
+
+elements.TrixEditorElement.formAssociated = config.editor.formAssociated
+
 function start() {
   if (!customElements.get("trix-toolbar")) {
     customElements.define("trix-toolbar", elements.TrixToolbarElement)
