diff --git a/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx b/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
index a3243ba61..91fffbab0 100644
--- a/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
+++ b/src/app/components/editor/autocomplete/RoomMentionAutocomplete.tsx
@@ -12,6 +12,7 @@ import { AutocompleteMenu } from './AutocompleteMenu';
 import { getMxIdServer, isRoomAlias } from '../../../utils/matrix';
 import { UseAsyncSearchOptions, useAsyncSearch } from '../../../hooks/useAsyncSearch';
 import { onTabPress } from '../../../utils/keyboard';
+import { useAutocompleteEnter } from '../../../hooks/useAutocompleteEnter';
 import { useKeyDown } from '../../../hooks/useKeyDown';
 import { mDirectAtom } from '../../../state/mDirectList';
 import { allRoomsAtom } from '../../../state/room-list/roomList';
@@ -126,19 +127,20 @@ export function RoomMentionAutocomplete({
     requestClose();
   };
 
-  useKeyDown(window, (evt: KeyboardEvent) => {
-    onTabPress(evt, () => {
-      if (autoCompleteRoomIds.length === 0) {
-        const alias = roomAliasFromQueryText(mx, query.text);
-        handleAutocomplete(alias, alias);
-        return;
-      }
-      const rId = autoCompleteRoomIds[0];
-      const r = mx.getRoom(rId);
-      const name = r?.name ?? rId;
-      handleAutocomplete(r?.getCanonicalAlias() ?? rId, name);
-    });
-  });
+  const pickTop = () => {
+    if (autoCompleteRoomIds.length === 0) {
+      const alias = roomAliasFromQueryText(mx, query.text);
+      handleAutocomplete(alias, alias);
+      return;
+    }
+    const rId = autoCompleteRoomIds[0];
+    const r = mx.getRoom(rId);
+    const name = r?.name ?? rId;
+    handleAutocomplete(r?.getCanonicalAlias() ?? rId, name);
+  };
+
+  useKeyDown(window, (evt: KeyboardEvent) => onTabPress(evt, pickTop));
+  useAutocompleteEnter(true, pickTop);
 
   return (
     <AutocompleteMenu headerContent={<Text size="L400">Rooms</Text>} requestClose={requestClose}>
diff --git a/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx b/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
index 663e49fb6..9ab348290 100644
--- a/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
+++ b/src/app/components/editor/autocomplete/UserMentionAutocomplete.tsx
@@ -13,6 +13,7 @@ import {
   useAsyncSearch,
 } from '../../../hooks/useAsyncSearch';
 import { onTabPress } from '../../../utils/keyboard';
+import { useAutocompleteEnter } from '../../../hooks/useAutocompleteEnter';
 import { createMentionElement, moveCursor, replaceWithElement } from '../utils';
 import { useKeyDown } from '../../../hooks/useKeyDown';
 import { getMxIdLocalPart, getMxIdServer, isUserId } from '../../../utils/matrix';
@@ -124,21 +125,24 @@ export function UserMentionAutocomplete({
     requestClose();
   };
 
-  useKeyDown(window, (evt: KeyboardEvent) => {
-    onTabPress(evt, () => {
-      if (query.text === 'room') {
-        handleAutocomplete(roomAliasOrId, '@room');
-        return;
-      }
-      if (autoCompleteMembers.length === 0) {
-        const userId = userIdFromQueryText(mx, query.text);
-        handleAutocomplete(userId, userId);
-        return;
-      }
-      const roomMember = autoCompleteMembers[0];
-      handleAutocomplete(roomMember.userId, roomMember.name);
-    });
-  });
+  const pickTop = () => {
+    if (query.text === 'room') {
+      handleAutocomplete(roomAliasOrId, '@room');
+      return;
+    }
+    if (autoCompleteMembers.length === 0) {
+      const userId = userIdFromQueryText(mx, query.text);
+      handleAutocomplete(userId, userId);
+      return;
+    }
+    const roomMember = autoCompleteMembers[0];
+    handleAutocomplete(roomMember.userId, getMemberName(room, roomMember.userId));
+  };
+
+  useKeyDown(window, (evt: KeyboardEvent) => onTabPress(evt, pickTop));
+  // The list always shows a suggestion (a member, or the typed id), so Enter
+  // always picks rather than sending "hey @bo".
+  useAutocompleteEnter(true, pickTop);
 
   const getName = (member: RoomMember) => getMemberName(room, member.userId);
 
diff --git a/src/app/features/room/CommandAutocomplete.tsx b/src/app/features/room/CommandAutocomplete.tsx
index 891c00f4a..a24f20c5e 100644
--- a/src/app/features/room/CommandAutocomplete.tsx
+++ b/src/app/features/room/CommandAutocomplete.tsx
@@ -14,6 +14,7 @@ import { UseAsyncSearchOptions, useAsyncSearch } from '../../hooks/useAsyncSearc
 import { useMatrixClient } from '../../hooks/useMatrixClient';
 import { useKeyDown } from '../../hooks/useKeyDown';
 import { onTabPress } from '../../utils/keyboard';
+import { useAutocompleteEnter } from '../../hooks/useAutocompleteEnter';
 
 type CommandAutoCompleteHandler = (commandName: string) => void;
 
@@ -60,15 +61,14 @@ export function CommandAutocomplete({
     requestClose();
   };
 
-  useKeyDown(window, (evt: KeyboardEvent) => {
-    onTabPress(evt, () => {
-      if (autoCompleteNames.length === 0) {
-        return;
-      }
-      const cmdName = autoCompleteNames[0];
-      handleAutocomplete(cmdName);
-    });
-  });
+  const pickTop = () => {
+    if (autoCompleteNames.length === 0) return;
+    handleAutocomplete(autoCompleteNames[0]);
+  };
+
+  useKeyDown(window, (evt: KeyboardEvent) => onTabPress(evt, pickTop));
+  // Only while suggestions show: with no match Enter must still send.
+  useAutocompleteEnter(autoCompleteNames.length > 0, pickTop);
 
   return autoCompleteNames.length === 0 ? null : (
     <AutocompleteMenu
diff --git a/src/app/hooks/useAutocompleteEnter.ts b/src/app/hooks/useAutocompleteEnter.ts
new file mode 100644
index 000000000..7746d831a
--- /dev/null
+++ b/src/app/hooks/useAutocompleteEnter.ts
@@ -0,0 +1,28 @@
+import { useEffect, useRef } from 'react';
+import { isKeyHotkey } from 'is-hotkey';
+
+/**
+ * Enter picks the top suggestion while an autocomplete list is showing, as in
+ * Discord / Slack / Element, instead of sending the half-typed text ("hey @bo").
+ *
+ * The listener runs in the window's capture phase so it sees Enter before the
+ * composer's own handler (which would submit), and only claims the key when
+ * `active` (the list has suggestions) — otherwise Enter sends as normal. IME
+ * composition and modified Enter (Shift/Ctrl/Alt/Meta) are left alone.
+ */
+export function useAutocompleteEnter(active: boolean, onSelect: () => void): void {
+  const selectRef = useRef(onSelect);
+  selectRef.current = onSelect;
+
+  useEffect(() => {
+    if (!active) return undefined;
+    const onKeyDown = (evt: KeyboardEvent) => {
+      if (evt.isComposing || !isKeyHotkey('enter', evt)) return;
+      evt.preventDefault();
+      evt.stopPropagation();
+      selectRef.current();
+    };
+    window.addEventListener('keydown', onKeyDown, true);
+    return () => window.removeEventListener('keydown', onKeyDown, true);
+  }, [active]);
+}