diff --git a/app/javascript/mastodon/components/form_fields/combobox.module.scss b/app/javascript/mastodon/components/form_fields/combobox.module.scss
index ef230a77b8..c14bac0cb6 100644
--- a/app/javascript/mastodon/components/form_fields/combobox.module.scss
+++ b/app/javascript/mastodon/components/form_fields/combobox.module.scss
@@ -26,7 +26,6 @@
   z-index: 9999;
   box-sizing: border-box;
   max-height: min(320px, 50dvh);
-  padding: 4px;
   border-radius: 4px;
   color: var(--color-text-primary);
   background: var(--color-bg-primary);
@@ -38,22 +37,18 @@
   overscroll-behavior-y: contain;
 }
 
-.groupLabel {
-  padding-block: 12px 4px;
-  padding-inline: 12px;
+.groupTitle {
+  padding: 8px 16px 4px;
   font-size: 13px;
   font-weight: bold;
   text-transform: uppercase;
-
-  ul:first-child > & {
-    padding-top: 4px;
-  }
 }
 
 .menuItem {
   display: flex;
   align-items: center;
   padding: 8px 12px;
+  margin-inline: 4px;
   gap: 12px;
   font-size: 14px;
   line-height: 20px;
@@ -62,6 +57,14 @@
   cursor: pointer;
   user-select: none;
 
+  &:first-child {
+    margin-top: 4px;
+  }
+
+  &:last-child {
+    margin-bottom: 4px;
+  }
+
   &[data-highlighted='true'] {
     background: var(--color-bg-overlay-highlight);
   }
diff --git a/app/javascript/mastodon/components/form_fields/combobox_field.stories.tsx b/app/javascript/mastodon/components/form_fields/combobox_field.stories.tsx
index 32fc736423..795cba727a 100644
--- a/app/javascript/mastodon/components/form_fields/combobox_field.stories.tsx
+++ b/app/javascript/mastodon/components/form_fields/combobox_field.stories.tsx
@@ -2,7 +2,7 @@ import { useCallback, useState } from 'react';
 
 import type { Meta, StoryObj } from '@storybook/react-vite';
 
-import { ComboboxField } from './combobox_field';
+import { ComboboxField, ComboboxMenuItem } from './combobox_field';
 
 interface Fruit {
   id: string;
@@ -60,7 +60,7 @@ const ComboboxDemo: React.FC<{ withGroups?: boolean }> = ({ withGroups }) => {
   }, []);
 
   const renderItem = useCallback(
-    (fruit: Fruit) => <span>{fruit.name}</span>,
+    (fruit: Fruit) => <ComboboxMenuItem>{fruit.name}</ComboboxMenuItem>,
     [],
   );
 
@@ -93,6 +93,7 @@ const ComboboxDemo: React.FC<{ withGroups?: boolean }> = ({ withGroups }) => {
 const meta = {
   title: 'Components/Form Fields/ComboboxField',
   component: ComboboxField,
+  subcomponents: { ComboboxMenuItem },
   render: () => <ComboboxDemo />,
 } satisfies Meta<typeof ComboboxField>;
 
diff --git a/app/javascript/mastodon/components/form_fields/combobox_field.tsx b/app/javascript/mastodon/components/form_fields/combobox_field.tsx
index 64cbb3ce8a..40199d47ed 100644
--- a/app/javascript/mastodon/components/form_fields/combobox_field.tsx
+++ b/app/javascript/mastodon/components/form_fields/combobox_field.tsx
@@ -1,6 +1,8 @@
 import {
+  createContext,
   forwardRef,
   useCallback,
+  useContext,
   useId,
   useMemo,
   useRef,
@@ -109,6 +111,58 @@ interface ComboboxProps<
 interface Props<Item extends ComboboxItem, GroupKey extends string>
   extends ComboboxProps<Item, GroupKey>, CommonFieldWrapperProps {}
 
+interface ComboboxItemPropsContext {
+  role: 'option';
+  'data-highlighted': boolean;
+  'aria-selected': boolean;
+  'aria-disabled': boolean;
+  'data-item-id': string;
+  onMouseEnter: React.MouseEventHandler<HTMLLIElement>;
+  onClick: React.MouseEventHandler<HTMLLIElement>;
+}
+
+const ComboboxItemPropsContext = createContext<ComboboxItemPropsContext | null>(
+  null,
+);
+
+export function useComboboxItemProps() {
+  const context = useContext(ComboboxItemPropsContext);
+
+  if (context === null) {
+    throw new Error(
+      'useComboboxItemProps must be used within a Combobox component',
+    );
+  }
+
+  return context;
+}
+
+export const ComboboxMenuItem: React.FC<{
+  className?: string;
+  children: React.ReactNode;
+}> = ({ className, children }) => {
+  const props = useComboboxItemProps();
+  return (
+    <li className={classNames(className, classes.menuItem)} {...props}>
+      {children}
+    </li>
+  );
+};
+
+export const ComboboxMenuGroupTitle: React.FC<
+  React.ComponentPropsWithoutRef<'li'>
+> = ({ className, children, ...otherProps }) => {
+  return (
+    <li
+      {...otherProps}
+      role='presentation'
+      className={classNames(className, classes.groupTitle)}
+    >
+      {children}
+    </li>
+  );
+};
+
 /**
  * The combobox field allows users to select one or more items
  * by searching or filtering a large or dynamic list of options.
@@ -371,7 +425,7 @@ const ComboboxWithRef = <Item extends ComboboxItem, GroupKey extends string>(
   const renderItems = (items: Item[]) =>
     items.map((item) => {
       const id = getItemId(item);
-      const isDisabled = getIsItemDisabled?.(item);
+      const isDisabled = getIsItemDisabled?.(item) ?? false;
       const isHighlighted = id === highlightedItemId;
       // If `getIsItemSelected` is defined, we assume 'multi-select'
       // behaviour and don't set `aria-selected` based on highlight,
@@ -380,23 +434,23 @@ const ComboboxWithRef = <Item extends ComboboxItem, GroupKey extends string>(
         ? getIsItemSelected(item)
         : isHighlighted;
       return (
-        // eslint-disable-next-line jsx-a11y/click-events-have-key-events
-        <li
+        <ComboboxItemPropsContext.Provider
           key={id}
-          role='option'
-          className={classes.menuItem}
-          data-highlighted={isHighlighted}
-          aria-selected={isSelected}
-          aria-disabled={isDisabled}
-          data-item-id={id}
-          onMouseEnter={handleItemMouseEnter}
-          onClick={handleSelectItem}
+          value={{
+            role: 'option',
+            'data-highlighted': isHighlighted,
+            'aria-selected': isSelected,
+            'aria-disabled': isDisabled,
+            'data-item-id': id,
+            onMouseEnter: handleItemMouseEnter,
+            onClick: handleSelectItem,
+          }}
         >
           {renderItem(item, {
             isSelected,
-            isDisabled: isDisabled ?? false,
+            isDisabled,
           })}
-        </li>
+        </ComboboxItemPropsContext.Provider>
       );
     });
 
@@ -498,16 +552,12 @@ const ComboboxWithRef = <Item extends ComboboxItem, GroupKey extends string>(
                         role='group'
                         aria-labelledby={hasTitle ? groupTitleId : undefined}
                       >
-                        {hasTitle && (
-                          <li
-                            role='presentation'
-                            className={classes.groupLabel}
-                          >
-                            {customGroupTitle ?? (
-                              <span id={groupTitleId}>{groupKey}</span>
-                            )}
-                          </li>
-                        )}
+                        {hasTitle &&
+                          (customGroupTitle ?? (
+                            <ComboboxMenuGroupTitle id={groupTitleId}>
+                              {groupKey}
+                            </ComboboxMenuGroupTitle>
+                          ))}
                         {renderItems(groupItems)}
                       </ul>
                     );
diff --git a/app/javascript/mastodon/features/account_edit/components/tag_search.tsx b/app/javascript/mastodon/features/account_edit/components/tag_search.tsx
index 2dd17c2a72..04befb4690 100644
--- a/app/javascript/mastodon/features/account_edit/components/tag_search.tsx
+++ b/app/javascript/mastodon/features/account_edit/components/tag_search.tsx
@@ -4,6 +4,7 @@ import { useCallback, useId, useState } from 'react';
 import { defineMessages, useIntl } from 'react-intl';
 
 import { Combobox } from '@/mastodon/components/form_fields';
+import { ComboboxMenuItem } from '@/mastodon/components/form_fields/combobox_field';
 import { useSearchTags } from '@/mastodon/hooks/useSearchTags';
 import type { TagSearchResult } from '@/mastodon/hooks/useSearchTags';
 import { addFeaturedTags } from '@/mastodon/reducers/slices/profile_edit';
@@ -77,4 +78,6 @@ export const AccountEditTagSearch: FC = () => {
   );
 };
 
-const renderItem = (item: TagSearchResult) => item.label ?? `#${item.name}`;
+const renderItem = (item: TagSearchResult) => (
+  <ComboboxMenuItem>{item.label ?? `#${item.name}`}</ComboboxMenuItem>
+);
diff --git a/app/javascript/mastodon/features/collections/editor/accounts.tsx b/app/javascript/mastodon/features/collections/editor/accounts.tsx
index a51f58c236..dddd0242e0 100644
--- a/app/javascript/mastodon/features/collections/editor/accounts.tsx
+++ b/app/javascript/mastodon/features/collections/editor/accounts.tsx
@@ -6,6 +6,7 @@ import { useHistory } from 'react-router-dom';
 
 import type { Map as ImmutableMap } from 'immutable';
 
+import { useComboboxItemProps } from '@/mastodon/components/form_fields/combobox_field';
 import type { ApiMutedAccountJSON } from 'mastodon/api_types/accounts';
 import type { ApiCollectionJSON } from 'mastodon/api_types/collections';
 import { AccountListItem } from 'mastodon/components/account_list_item';
@@ -67,18 +68,18 @@ const AddedAccountItem: React.FC<{
 const SuggestedAccountItem: React.FC<{ id: string }> = ({ id }) => {
   const account = useAccount(id);
   const handle = useAccountHandle(account, domain);
+  const comboboxItemProps = useComboboxItemProps();
 
   if (!account) return null;
 
   return (
-    <ListItemWrapper
-      className={classes.suggestion}
-      icon={<Avatar account={account} size={40} />}
-    >
-      <ListItemContent subtitle={handle}>
-        <DisplayName account={account} variant='simple' />
-      </ListItemContent>
-    </ListItemWrapper>
+    <li {...comboboxItemProps} className={classes.suggestion}>
+      <ListItemWrapper icon={<Avatar account={account} size={40} />}>
+        <ListItemContent subtitle={handle}>
+          <DisplayName account={account} variant='simple' />
+        </ListItemContent>
+      </ListItemWrapper>
+    </li>
   );
 };
 
@@ -158,11 +159,13 @@ const renderGroupTitle = (groupKey: GroupKey, titleId: string) => {
   }
 
   return (
-    <ListItemWrapper className={classes.suggestionGroup}>
-      <ListItemContent id={titleId} subtitle={description}>
-        {title}
-      </ListItemContent>
-    </ListItemWrapper>
+    <li role='presentation'>
+      <ListItemWrapper className={classes.suggestionGroup}>
+        <ListItemContent id={titleId} subtitle={description}>
+          {title}
+        </ListItemContent>
+      </ListItemWrapper>
+    </li>
   );
 };
 
diff --git a/app/javascript/mastodon/features/collections/editor/details.tsx b/app/javascript/mastodon/features/collections/editor/details.tsx
index ae944ba41f..42ef8db970 100644
--- a/app/javascript/mastodon/features/collections/editor/details.tsx
+++ b/app/javascript/mastodon/features/collections/editor/details.tsx
@@ -6,6 +6,7 @@ import { useHistory } from 'react-router-dom';
 
 import { isFulfilled } from '@reduxjs/toolkit';
 
+import { ComboboxMenuItem } from '@/mastodon/components/form_fields/combobox_field';
 import { languages } from '@/mastodon/initial_state';
 import {
   hasSpecialCharacters,
@@ -373,7 +374,9 @@ const TopicField: React.FC = () => {
   );
 };
 
-const renderTagItem = (item: TagSearchResult) => item.label ?? `#${item.name}`;
+const renderTagItem = (item: TagSearchResult) => (
+  <ComboboxMenuItem>{item.label ?? `#${item.name}`}</ComboboxMenuItem>
+);
 
 const LanguageField: React.FC = () => {
   const dispatch = useAppDispatch();
diff --git a/app/javascript/mastodon/features/collections/editor/styles.module.scss b/app/javascript/mastodon/features/collections/editor/styles.module.scss
index 1befc06cc1..d4b1d2d7f3 100644
--- a/app/javascript/mastodon/features/collections/editor/styles.module.scss
+++ b/app/javascript/mastodon/features/collections/editor/styles.module.scss
@@ -60,17 +60,20 @@
 }
 
 .suggestion {
-  padding: 4px 0;
+  cursor: pointer;
+  user-select: none;
+  border-bottom: 1px solid var(--color-border-primary);
 
-  [aria-disabled='true'] & {
+  &[data-highlighted='true'] {
+    background: var(--color-bg-overlay-highlight);
+  }
+
+  &[aria-disabled='true'] {
     opacity: 0.6;
+    cursor: not-allowed;
   }
 }
 
 .suggestionGroup {
-  padding: 4px 0;
-
-  // Undo default group styles:
-  font-weight: 400;
-  text-transform: none;
+  padding-bottom: 4px;
 }