diff --git a/docs/reference/hooks.md b/docs/reference/hooks.md
index 85f47e9966..51ce4e9de0 100644
--- a/docs/reference/hooks.md
+++ b/docs/reference/hooks.md
@@ -466,30 +466,6 @@ Hooks for customising the editing interface for pages and snippets.
 
 Rich text fields in Wagtail work with a list of 'feature' identifiers that determine which editing controls are available in the editor, and which elements are allowed in the output; for example, a rich text field defined as `RichTextField(features=['h2', 'h3', 'bold', 'italic', 'link'])` would allow headings, bold / italic formatting and links, but not (for example) bullet lists or images. The `register_rich_text_features` hook allows new feature identifiers to be defined - see [](rich_text_features) for details.
 
-(insert_editor_css)=
-
-### `insert_editor_css`
-
-Add additional CSS files or snippets to the page editor.
-
-```python
-from django.templatetags.static import static
-from django.utils.html import format_html
-
-from wagtail import hooks
-
-@hooks.register('insert_editor_css')
-def editor_css():
-    return format_html(
-        '<link rel="stylesheet" href="{}">',
-        static('demo/css/vendor/font-awesome/css/font-awesome.min.css')
-    )
-```
-
-```{note}
-The `insert_editor_css` hook is deprecated and will be removed in a future release. We recommend using [](insert_global_admin_css) instead.
-```
-
 (insert_global_admin_css)=
 
 ### `insert_global_admin_css`
diff --git a/wagtail/admin/templates/wagtailadmin/admin_base.html b/wagtail/admin/templates/wagtailadmin/admin_base.html
index d2423a9053..f6c3707c12 100644
--- a/wagtail/admin/templates/wagtailadmin/admin_base.html
+++ b/wagtail/admin/templates/wagtailadmin/admin_base.html
@@ -5,7 +5,6 @@
     <link rel="stylesheet" href="{% versioned_static 'wagtailadmin/css/core.css' %}">
 
     {% hook_output 'insert_global_admin_css' %}
-    {% hook_output 'insert_editor_css' %}
 
     {% block extra_css %}{% endblock %}
 {% endblock %}
diff --git a/wagtail/admin/templates/wagtailadmin/userbar/base.html b/wagtail/admin/templates/wagtailadmin/userbar/base.html
index 520f2c1425..d4d7dfe91e 100644
--- a/wagtail/admin/templates/wagtailadmin/userbar/base.html
+++ b/wagtail/admin/templates/wagtailadmin/userbar/base.html
@@ -5,7 +5,6 @@
         <div class="w-userbar w-userbar--{{ position|default:'bottom-right' }} {% admin_theme_classname %}" data-wagtail-userbar part="userbar">
             <link rel="stylesheet" href="{% versioned_static 'wagtailadmin/css/core.css' %}">
             {% hook_output 'insert_global_admin_css' %}
-            {% hook_output 'insert_editor_css' %}
             <div class="w-userbar-nav">
 
                 <svg class="w-hidden">
diff --git a/wagtail/admin/templatetags/wagtailadmin_tags.py b/wagtail/admin/templatetags/wagtailadmin_tags.py
index 40d646be19..2afcf6eca1 100644
--- a/wagtail/admin/templatetags/wagtailadmin_tags.py
+++ b/wagtail/admin/templatetags/wagtailadmin_tags.py
@@ -278,12 +278,6 @@ def hook_output(hook_name):
     """
     snippets = [fn() for fn in hooks.get_hooks(hook_name)]
 
-    if hook_name == "insert_editor_css" and snippets:
-        warn(
-            "The `insert_editor_css` hook is deprecated - use `insert_global_admin_css` instead.",
-            category=RemovedInWagtail60Warning,
-        )
-
     return mark_safe("".join(snippets))
 
 
diff --git a/wagtail/admin/tests/tests.py b/wagtail/admin/tests/tests.py
index a8dbd9f0ad..8461d78370 100644
--- a/wagtail/admin/tests/tests.py
+++ b/wagtail/admin/tests/tests.py
@@ -11,7 +11,6 @@ from django.urls import reverse, reverse_lazy
 from django.utils.translation import gettext_lazy as _
 from taggit.models import Tag
 
-from wagtail import hooks
 from wagtail.admin.auth import user_has_any_page_permission
 from wagtail.admin.mail import send_mail
 from wagtail.admin.menu import MenuItem
@@ -19,7 +18,6 @@ from wagtail.models import Page
 from wagtail.test.testapp.models import RestaurantTag
 from wagtail.test.utils import WagtailTestUtils
 from wagtail.utils.deprecation import (
-    RemovedInWagtail60Warning,
     RemovedInWagtail70Warning,
 )
 
@@ -160,20 +158,6 @@ class TestEditorHooks(WagtailTestUtils, TestCase):
         self.assertEqual(response.status_code, 200)
         self.assertContains(response, '<script src="/path/to/my/custom.js"></script>')
 
-    def test_deprecated_editor_css_hook(self):
-        def css_hook():
-            return '<link rel="stylesheet" href="/some/custom.css">'
-
-        with self.assertWarnsMessage(
-            RemovedInWagtail60Warning,
-            "The `insert_editor_css` hook is deprecated - use `insert_global_admin_css` instead.",
-        ):
-            with hooks.register_temporarily("insert_editor_css", css_hook):
-                response = self.client.get(reverse("wagtailadmin_home"))
-                self.assertContains(
-                    response, '<link rel="stylesheet" href="/some/custom.css">'
-                )
-
 
 class TestSendMail(TestCase):
     def test_send_email(self):