diff --git a/apps/web/src/components/NotebookPane.tsx b/apps/web/src/components/NotebookPane.tsx
index 2a543ea7..9c7fa805 100644
--- a/apps/web/src/components/NotebookPane.tsx
+++ b/apps/web/src/components/NotebookPane.tsx
@@ -248,14 +248,17 @@ const SidebarCollapseButton = ({
   onToggle,
   className,
   tooltipSide = "bottom",
+  shortcutLabel,
 }: {
   collapsed: boolean;
   onToggle: () => void;
   className?: string;
   tooltipSide?: "top" | "right" | "bottom" | "left";
+  shortcutLabel?: string;
 }) => {
   const { t } = useTranslation();
   const label = t(collapsed ? "notebookPane.expandSidebar" : "notebookPane.collapseSidebar");
+  const tooltipLabel = shortcutLabel ? `${label} (${shortcutLabel})` : label;
 
   return (
     <TooltipProvider delayDuration={0} skipDelayDuration={0}>
@@ -275,7 +278,7 @@ const SidebarCollapseButton = ({
             {collapsed ? <ChevronsRight className="h-4 w-4" aria-hidden="true" /> : <ChevronsLeft className="h-4 w-4" aria-hidden="true" />}
           </button>
         </TooltipTrigger>
-        <TooltipContent side={tooltipSide}>{label}</TooltipContent>
+        <TooltipContent side={tooltipSide}>{tooltipLabel}</TooltipContent>
       </Tooltip>
     </TooltipProvider>
   );
@@ -512,6 +515,7 @@ export const NotebookPane = ({
   isResettingDemo = false,
   collapsed = false,
   onToggleCollapsed,
+  collapseShortcutLabel,
 }: {
   repository: EdgeEverRepository;
   user: AuthUser | null;
@@ -550,6 +554,7 @@ export const NotebookPane = ({
   isResettingDemo?: boolean;
   collapsed?: boolean;
   onToggleCollapsed?: () => void;
+  collapseShortcutLabel?: string;
 }) => {
   const { t } = useTranslation();
   const showDescendantNotes = useShowDescendantNotesPreference();
@@ -946,7 +951,7 @@ export const NotebookPane = ({
                   notice={deployedUpdateUnseen}
                   onClick={onOpenSettings}
                 />
-                <SidebarCollapseButton collapsed onToggle={onToggleCollapsed} className="h-9 w-9" tooltipSide="right" />
+                <SidebarCollapseButton collapsed onToggle={onToggleCollapsed} className="h-9 w-9" tooltipSide="right" shortcutLabel={collapseShortcutLabel} />
               </div>
             </nav>
           </div>
@@ -1176,7 +1181,7 @@ export const NotebookPane = ({
             </button>
             <DesktopUpdateNotice />
             {onToggleCollapsed ? (
-              <SidebarCollapseButton collapsed={collapsed} onToggle={onToggleCollapsed} className="hidden lg:inline-flex" />
+              <SidebarCollapseButton collapsed={collapsed} onToggle={onToggleCollapsed} className="hidden lg:inline-flex" shortcutLabel={collapseShortcutLabel} />
             ) : null}
           </div>
         </div>
diff --git a/apps/web/src/components/WorkspaceApp.tsx b/apps/web/src/components/WorkspaceApp.tsx
index 8aca7455..8da6de73 100644
--- a/apps/web/src/components/WorkspaceApp.tsx
+++ b/apps/web/src/components/WorkspaceApp.tsx
@@ -71,6 +71,8 @@ import {
   isTextEntryTarget,
   getSearchShortcutScope,
   getShortcutActionForEvent,
+  formatShortcutBinding,
+  canToggleNotebookSidebar,
   getNotebookDropSortOrder,
   getNotebookMoveOptions,
   getMemoIdsNeedingMove,
@@ -2810,6 +2812,19 @@ export const WorkspaceApp = ({
         return;
       }
 
+      if (action === "toggleSidebar") {
+        event.preventDefault();
+        if (
+          event.repeat
+          || event.isComposing
+          || !canToggleNotebookSidebar({ isDesktop, focusModeActive: desktopFocusModeActive })
+        ) {
+          return;
+        }
+        setNotebookSidebarCollapsed(!notebookSidebarCollapsed);
+        return;
+      }
+
       if (action === "focusSearch") {
         event.preventDefault();
         if (getSearchShortcutScope(selectedMemoId) === "memo-list") {
@@ -2868,6 +2883,10 @@ export const WorkspaceApp = ({
     handleGlobalSearch,
     handleMobileSearch,
     shortcutSettings,
+    isDesktop,
+    desktopFocusModeActive,
+    notebookSidebarCollapsed,
+    setNotebookSidebarCollapsed,
     emptyTrashConfirmationOpen,
     memoDeleteConfirmation,
     memoView,
@@ -3083,6 +3102,7 @@ export const WorkspaceApp = ({
                   isResettingDemo={resetDemoMutation.isPending}
                   collapsed={desktopNotebookSidebarCollapsed}
                   onToggleCollapsed={() => setNotebookSidebarCollapsed(!notebookSidebarCollapsed)}
+                  collapseShortcutLabel={formatShortcutBinding(shortcutSettings.toggleSidebar)}
                 />
               </Suspense>
             )}
diff --git a/apps/web/src/lib/app-helpers.test.mjs b/apps/web/src/lib/app-helpers.test.mjs
index 3bc0b3a6..9506a990 100644
--- a/apps/web/src/lib/app-helpers.test.mjs
+++ b/apps/web/src/lib/app-helpers.test.mjs
@@ -1,4 +1,5 @@
 import { afterEach, describe, expect, test } from "bun:test";
+import { readFileSync } from "node:fs";
 import {
   DEFAULT_SHORTCUT_SETTINGS,
   DESKTOP_FOCUS_MODE_STORAGE_KEY,
@@ -14,6 +15,7 @@ import {
   SHORTCUT_SETTINGS_STORAGE_KEY,
   getSearchShortcutScope,
   getShortcutActionForEvent,
+  canToggleNotebookSidebar,
   getNotebookSortComparator,
   readEditorContentAlignmentPreference,
   readNotebookSortPreference,
@@ -445,6 +447,12 @@ describe("workspace shortcut preferences", () => {
       shift: true,
       alt: false,
     });
+    expect(DEFAULT_SHORTCUT_SETTINGS.toggleSidebar).toEqual({
+      key: "\\",
+      ctrlOrMeta: true,
+      shift: false,
+      alt: false,
+    });
   });
 
   test("migrates the unreleased reading protection shortcut without replacing custom bindings", () => {
@@ -532,6 +540,21 @@ describe("workspace shortcut preferences", () => {
       keyboardEvent("!", { code: "Digit1", ctrlKey: true, shiftKey: true }),
       DEFAULT_SHORTCUT_SETTINGS,
     )).toBe("toggleOutline");
+    expect(getShortcutActionForEvent(
+      keyboardEvent("\\", { metaKey: true }),
+      DEFAULT_SHORTCUT_SETTINGS,
+    )).toBe("toggleSidebar");
+  });
+
+  test("toggles the sidebar only when it is visible", () => {
+    expect(canToggleNotebookSidebar({ isDesktop: true, focusModeActive: false })).toBe(true);
+    // Focus Mode hides the sidebar, so the shortcut must not change its saved state.
+    expect(canToggleNotebookSidebar({ isDesktop: true, focusModeActive: true })).toBe(false);
+    expect(canToggleNotebookSidebar({ isDesktop: false, focusModeActive: false })).toBe(false);
+    expect(canToggleNotebookSidebar({ isDesktop: false, focusModeActive: true })).toBe(false);
+    // The workspace checks the same flag that hides the sidebar in its layout.
+    const workspaceSource = readFileSync(new URL("../components/WorkspaceApp.tsx", import.meta.url), "utf8");
+    expect(workspaceSource).toContain("canToggleNotebookSidebar({ isDesktop, focusModeActive: desktopFocusModeActive })");
   });
 });
 
diff --git a/apps/web/src/lib/app-helpers.ts b/apps/web/src/lib/app-helpers.ts
index 153bfab4..3f6a3d9b 100644
--- a/apps/web/src/lib/app-helpers.ts
+++ b/apps/web/src/lib/app-helpers.ts
@@ -26,7 +26,8 @@ export type ShortcutAction =
   | "saveAndSync"
   | "toggleReadingProtection"
   | "toggleEditorMode"
-  | "toggleOutline";
+  | "toggleOutline"
+  | "toggleSidebar";
 export type ShortcutBinding = {
   key: string;
   ctrlOrMeta: boolean;
@@ -190,6 +191,7 @@ export const getShortcutActionOptions = (
   { value: "toggleReadingProtection", label: t("shortcuts.actions.toggleReadingProtection.label") },
   { value: "toggleEditorMode", label: t("shortcuts.actions.toggleEditorMode.label") },
   { value: "toggleOutline", label: t("shortcuts.actions.toggleOutline.label") },
+  { value: "toggleSidebar", label: t("shortcuts.actions.toggleSidebar.label") },
 ];
 
 export const DEFAULT_SHORTCUT_SETTINGS: ShortcutSettings = {
@@ -206,6 +208,7 @@ export const DEFAULT_SHORTCUT_SETTINGS: ShortcutSettings = {
   toggleReadingProtection: { key: "e", ctrlOrMeta: true, shift: false, alt: false },
   toggleEditorMode: { key: "/", ctrlOrMeta: true, shift: false, alt: false },
   toggleOutline: { key: "1", ctrlOrMeta: true, shift: true, alt: false },
+  toggleSidebar: { key: "\\", ctrlOrMeta: true, shift: false, alt: false },
 };
 
 const LEGACY_READING_PROTECTION_SHORTCUT: ShortcutBinding = {
@@ -233,6 +236,7 @@ const SHORTCUT_ACTION_VALUES: ShortcutAction[] = [
   "toggleReadingProtection",
   "toggleEditorMode",
   "toggleOutline",
+  "toggleSidebar",
 ];
 
 export const isDefaultMemoTitle = (title: string | null | undefined) => title?.trim() === DEFAULT_MEMO_TITLE;
@@ -583,6 +587,13 @@ export const shortcutBindingsEqual = (first: ShortcutBinding, second: ShortcutBi
   first.shift === second.shift &&
   first.alt === second.alt;
 
+// The sidebar shortcut only acts when the sidebar can be seen: Focus Mode hides
+// it, so toggling there would change a persisted state without any feedback.
+export const canToggleNotebookSidebar = ({ isDesktop, focusModeActive }: {
+  isDesktop: boolean;
+  focusModeActive: boolean;
+}) => isDesktop && !focusModeActive;
+
 export const getShortcutActionForEvent = (event: KeyboardEvent, settings: ShortcutSettings): ShortcutAction | null => {
   const eventBinding = shortcutBindingFromKeyboardEvent(event);
 
diff --git a/packages/shared/src/i18n/en-US.ts b/packages/shared/src/i18n/en-US.ts
index 1b70e904..3bdf1c36 100644
--- a/packages/shared/src/i18n/en-US.ts
+++ b/packages/shared/src/i18n/en-US.ts
@@ -1681,6 +1681,7 @@ export const enUS = {
       toggleReadingProtection: { label: "Toggle reading protection" },
       toggleEditorMode: { label: "Switch editor mode" },
       toggleOutline: { label: "Show/hide document outline" },
+      toggleSidebar: { label: "Show/hide sidebar" },
     },
   },
   quickSwitcher: {
diff --git a/packages/shared/src/i18n/ja.ts b/packages/shared/src/i18n/ja.ts
index e4a35334..83c7d9fe 100644
--- a/packages/shared/src/i18n/ja.ts
+++ b/packages/shared/src/i18n/ja.ts
@@ -1681,6 +1681,7 @@ export const ja = {
       toggleReadingProtection: { label: "閲覧保護を切り替え" },
       toggleEditorMode: { label: "エディタモードを切り替え" },
       toggleOutline: { label: "ドキュメントアウトラインの表示/非表示" },
+      toggleSidebar: { label: "サイドバーの表示/非表示" },
     },
   },
   quickSwitcher: {
diff --git a/packages/shared/src/i18n/zh-CN.ts b/packages/shared/src/i18n/zh-CN.ts
index 890435fb..b95021a5 100644
--- a/packages/shared/src/i18n/zh-CN.ts
+++ b/packages/shared/src/i18n/zh-CN.ts
@@ -1681,6 +1681,7 @@ export const zhCN = {
       toggleReadingProtection: { label: "切换阅读保护" },
       toggleEditorMode: { label: "切换编辑模式" },
       toggleOutline: { label: "显示/隐藏文档大纲" },
+      toggleSidebar: { label: "显示/隐藏侧边栏" },
     },
   },
   quickSwitcher: {