diff --git a/app/src/components/layout/shell/CollapsedNavRail.tsx b/app/src/components/layout/shell/CollapsedNavRail.tsx
index c9c71fa1f..a2019f61f 100644
--- a/app/src/components/layout/shell/CollapsedNavRail.tsx
+++ b/app/src/components/layout/shell/CollapsedNavRail.tsx
@@ -6,6 +6,7 @@ import { useT } from '../../../lib/i18n/I18nContext';
 import { trackEvent } from '../../../services/analytics';
 import { useAppSelector } from '../../../store/hooks';
 import { selectUnreadCount } from '../../../store/notificationSlice';
+import { Tooltip } from '../../ui';
 import { NavIcon } from './navIcons';
 import { useHomeNav } from './useHomeNav';
 
@@ -58,63 +59,65 @@ export default function CollapsedNavRail() {
   return (
     <nav className="flex flex-col items-center gap-0.5" aria-label={t('nav.home')}>
       {/* Home */}
-      <button
-        type="button"
-        onClick={handleHome}
-        title={t('nav.home')}
-        aria-label={t('nav.home')}
-        aria-current={homeActive ? 'page' : undefined}
-        className={`${RAIL_BTN} ${
-          homeActive
-            ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
-            : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
-        }`}>
-        <NavIcon id="home" className="h-4 w-4" />
-      </button>
+      <Tooltip label={t('nav.home')}>
+        <button
+          type="button"
+          onClick={handleHome}
+          aria-label={t('nav.home')}
+          aria-current={homeActive ? 'page' : undefined}
+          className={`${RAIL_BTN} ${
+            homeActive
+              ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
+              : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
+          }`}>
+          <NavIcon id="home" className="h-4 w-4" />
+        </button>
+      </Tooltip>
 
       {/* Wallet shortcut — mirrors SidebarHeader wallet button for collapsed state. */}
-      <button
-        type="button"
-        onClick={() => navigate('/settings/wallet-balances')}
-        title={t('nav.wallet')}
-        aria-label={t('nav.wallet')}
-        aria-current={
-          matchActive('/settings/wallet-balances', location.pathname) ? 'page' : undefined
-        }
-        data-analytics-id="collapsed-rail-wallet"
-        className={`${RAIL_BTN} ${
-          matchActive('/settings/wallet-balances', location.pathname)
-            ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
-            : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
-        }`}>
-        <NavIcon id="wallet" className="h-4 w-4" />
-      </button>
+      <Tooltip label={t('nav.wallet')}>
+        <button
+          type="button"
+          onClick={() => navigate('/settings/wallet-balances')}
+          aria-label={t('nav.wallet')}
+          aria-current={
+            matchActive('/settings/wallet-balances', location.pathname) ? 'page' : undefined
+          }
+          data-analytics-id="collapsed-rail-wallet"
+          className={`${RAIL_BTN} ${
+            matchActive('/settings/wallet-balances', location.pathname)
+              ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
+              : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
+          }`}>
+          <NavIcon id="wallet" className="h-4 w-4" />
+        </button>
+      </Tooltip>
 
       {/* Primary nav destinations */}
       {tabs.map(tab => {
         const active = matchActive(tab.path, location.pathname);
         const showBadge = tab.id === 'notifications' && unreadCount > 0;
         return (
-          <button
-            key={tab.id}
-            type="button"
-            data-walkthrough={tab.walkthroughAttr}
-            onClick={() => handleClick(tab, active)}
-            title={tab.label}
-            aria-label={tab.label}
-            aria-current={active ? 'page' : undefined}
-            className={`${RAIL_BTN} ${
-              active
-                ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
-                : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
-            }`}>
-            <NavIcon id={tab.id} className="h-4 w-4" />
-            {showBadge && (
-              <span className="absolute -right-0.5 -top-0.5 flex h-[13px] min-w-[13px] items-center justify-center rounded-full bg-coral-500 px-1 text-[9px] font-bold leading-none text-white">
-                {unreadCount > 9 ? '9+' : unreadCount}
-              </span>
-            )}
-          </button>
+          <Tooltip key={tab.id} label={tab.label}>
+            <button
+              type="button"
+              data-walkthrough={tab.walkthroughAttr}
+              onClick={() => handleClick(tab, active)}
+              aria-label={tab.label}
+              aria-current={active ? 'page' : undefined}
+              className={`${RAIL_BTN} ${
+                active
+                  ? 'bg-white text-stone-900 shadow-sm dark:bg-neutral-800 dark:text-neutral-100'
+                  : 'text-stone-500 hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200'
+              }`}>
+              <NavIcon id={tab.id} className="h-4 w-4" />
+              {showBadge && (
+                <span className="absolute -right-0.5 -top-0.5 flex h-[13px] min-w-[13px] items-center justify-center rounded-full bg-coral-500 px-1 text-[9px] font-bold leading-none text-white">
+                  {unreadCount > 9 ? '9+' : unreadCount}
+                </span>
+              )}
+            </button>
+          </Tooltip>
         );
       })}
 
diff --git a/app/src/components/layout/shell/RootShellLayout.tsx b/app/src/components/layout/shell/RootShellLayout.tsx
index 8a372cfbf..7738f2cd5 100644
--- a/app/src/components/layout/shell/RootShellLayout.tsx
+++ b/app/src/components/layout/shell/RootShellLayout.tsx
@@ -9,6 +9,7 @@ import {
   setSidebarWidth,
   toggleSidebar,
 } from '../../../store/layoutSlice';
+import { Tooltip } from '../../ui';
 import CollapsedNavRail from './CollapsedNavRail';
 
 // `app-shell` (not the older `root-shell`) so the persisted geometry seeds
@@ -178,23 +179,24 @@ export default function RootShellLayout({ sidebar, children }: RootShellLayoutPr
           above the HTML layer — starts to its right and never covers it. */}
       {!isOpen && (
         <div className="flex w-9 flex-none flex-col items-center gap-0.5 border-r border-stone-200 bg-white pt-2 dark:border-neutral-800 dark:bg-neutral-900">
-          <button
-            type="button"
-            onClick={() => dispatch(setSidebarVisible({ id: LAYOUT_ID, visible: true }))}
-            data-testid="root-shell-reopen"
-            data-analytics-id="root-shell-reopen-sidebar"
-            aria-label={t('layout.showSidebar')}
-            title={t('layout.showSidebar')}
-            className="flex h-8 w-8 items-center justify-center rounded-lg text-stone-500 transition-colors hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200">
-            <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-              <path
-                strokeLinecap="round"
-                strokeLinejoin="round"
-                strokeWidth={1.8}
-                d="M9 5l7 7-7 7"
-              />
-            </svg>
-          </button>
+          <Tooltip label={t('layout.showSidebar')}>
+            <button
+              type="button"
+              onClick={() => dispatch(setSidebarVisible({ id: LAYOUT_ID, visible: true }))}
+              data-testid="root-shell-reopen"
+              data-analytics-id="root-shell-reopen-sidebar"
+              aria-label={t('layout.showSidebar')}
+              className="flex h-8 w-8 items-center justify-center rounded-lg text-stone-500 transition-colors hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200">
+              <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+                <path
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                  strokeWidth={1.8}
+                  d="M9 5l7 7-7 7"
+                />
+              </svg>
+            </button>
+          </Tooltip>
           {/* Keep the primary nav reachable while collapsed: an icon-only rail. */}
           <div className="mt-1 w-full border-t border-stone-200/70 pt-1 dark:border-neutral-800/70">
             <CollapsedNavRail />
diff --git a/app/src/components/layout/shell/SidebarHeader.test.tsx b/app/src/components/layout/shell/SidebarHeader.test.tsx
index e8ba41253..08e2abec2 100644
--- a/app/src/components/layout/shell/SidebarHeader.test.tsx
+++ b/app/src/components/layout/shell/SidebarHeader.test.tsx
@@ -46,6 +46,8 @@ describe('SidebarHeader', () => {
     renderWithProviders(<SidebarHeader />, { initialEntries: ['/home'] });
     const btn = screen.getByRole('button', { name: 'nav.wallet' });
     expect(btn).toHaveAttribute('aria-label', 'nav.wallet');
+    // The styled <Tooltip> wrapper re-applies a native `title` fallback so the
+    // label still surfaces if the portal pill is occluded by a CEF webview.
     expect(btn).toHaveAttribute('title', 'nav.wallet');
   });
 
diff --git a/app/src/components/layout/shell/SidebarHeader.tsx b/app/src/components/layout/shell/SidebarHeader.tsx
index 9b7ab3075..30396437c 100644
--- a/app/src/components/layout/shell/SidebarHeader.tsx
+++ b/app/src/components/layout/shell/SidebarHeader.tsx
@@ -1,6 +1,7 @@
 import { useNavigate } from 'react-router-dom';
 
 import { useT } from '../../../lib/i18n/I18nContext';
+import { Tooltip } from '../../ui';
 import { useRootSidebar } from './RootShellLayout';
 import { useHomeNav } from './useHomeNav';
 
@@ -8,8 +9,9 @@ const ICON_BTN =
   'flex h-7 w-7 flex-none items-center justify-center rounded-md text-stone-500 transition-colors hover:bg-stone-100 hover:text-stone-700 dark:text-neutral-400 dark:hover:bg-neutral-800/60 dark:hover:text-neutral-200';
 
 /**
- * Thin utility header at the top of the root sidebar: jump Home, open Settings,
- * and collapse the sidebar. Language is chosen from Settings, not here.
+ * Thin utility header at the top of the root sidebar: jump Home, open the
+ * wallet, open Settings, and collapse the sidebar. Language is chosen from
+ * Settings, not here.
  */
 export default function SidebarHeader() {
   const { t } = useT();
@@ -19,82 +21,86 @@ export default function SidebarHeader() {
 
   return (
     <div className="flex items-center justify-between gap-1 px-2 py-1.5">
-      <button
-        type="button"
-        onClick={handleHome}
-        className={ICON_BTN}
-        data-analytics-id="sidebar-header-home"
-        aria-label={t('nav.home')}
-        title={t('nav.home')}>
-        <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-          <path
-            strokeLinecap="round"
-            strokeLinejoin="round"
-            strokeWidth={1.8}
-            d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-4 0a2 2 0 01-2-2v-4a2 2 0 012-2h2a2 2 0 012 2v4a2 2 0 01-2 2h-2z"
-          />
-        </svg>
-      </button>
+      <Tooltip label={t('nav.home')}>
+        <button
+          type="button"
+          onClick={handleHome}
+          className={ICON_BTN}
+          data-analytics-id="sidebar-header-home"
+          aria-label={t('nav.home')}>
+          <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+            <path
+              strokeLinecap="round"
+              strokeLinejoin="round"
+              strokeWidth={1.8}
+              d="M3 12l2-2m0 0l7-7 7 7M5 10v10a1 1 0 001 1h3m10-11l2 2m-2-2v10a1 1 0 01-1 1h-3m-4 0a2 2 0 01-2-2v-4a2 2 0 012-2h2a2 2 0 012 2v4a2 2 0 01-2 2h-2z"
+            />
+          </svg>
+        </button>
+      </Tooltip>
 
       <div className="flex items-center gap-0.5">
         {/* Wallet shortcut — one-click access to wallet balances. */}
-        <button
-          type="button"
-          onClick={() => navigate('/settings/wallet-balances')}
-          className={ICON_BTN}
-          data-analytics-id="sidebar-header-wallet"
-          aria-label={t('nav.wallet')}
-          title={t('nav.wallet')}>
-          <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path
-              strokeLinecap="round"
-              strokeLinejoin="round"
-              strokeWidth={1.8}
-              d="M3 10h18M7 15h1m4 0h1m-7 4h12a3 3 0 003-3V8a3 3 0 00-3-3H6a3 3 0 00-3 3v8a3 3 0 003 3z"
-            />
-          </svg>
-        </button>
+        <Tooltip label={t('nav.wallet')}>
+          <button
+            type="button"
+            onClick={() => navigate('/settings/wallet-balances')}
+            className={ICON_BTN}
+            data-analytics-id="sidebar-header-wallet"
+            aria-label={t('nav.wallet')}>
+            <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path
+                strokeLinecap="round"
+                strokeLinejoin="round"
+                strokeWidth={1.8}
+                d="M3 10h18M7 15h1m4 0h1m-7 4h12a3 3 0 003-3V8a3 3 0 00-3-3H6a3 3 0 00-3 3v8a3 3 0 003 3z"
+              />
+            </svg>
+          </button>
+        </Tooltip>
 
-        <button
-          type="button"
-          onClick={() => navigate('/settings')}
-          className={ICON_BTN}
-          data-analytics-id="sidebar-header-settings"
-          aria-label={t('nav.settings')}
-          title={t('nav.settings')}>
-          <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path
-              strokeLinecap="round"
-              strokeLinejoin="round"
-              strokeWidth={1.8}
-              d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z"
-            />
-            <path
-              strokeLinecap="round"
-              strokeLinejoin="round"
-              strokeWidth={1.8}
-              d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"
-            />
-          </svg>
-        </button>
+        <Tooltip label={t('nav.settings')}>
+          <button
+            type="button"
+            onClick={() => navigate('/settings')}
+            className={ICON_BTN}
+            data-analytics-id="sidebar-header-settings"
+            aria-label={t('nav.settings')}>
+            <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path
+                strokeLinecap="round"
+                strokeLinejoin="round"
+                strokeWidth={1.8}
+                d="M10.325 4.317c.426-1.756 2.924-1.756 3.35 0a1.724 1.724 0 002.573 1.066c1.543-.94 3.31.826 2.37 2.37a1.724 1.724 0 001.065 2.572c1.756.426 1.756 2.924 0 3.35a1.724 1.724 0 00-1.066 2.573c.94 1.543-.826 3.31-2.37 2.37a1.724 1.724 0 00-2.572 1.065c-.426 1.756-2.924 1.756-3.35 0a1.724 1.724 0 00-2.573-1.066c-1.543.94-3.31-.826-2.37-2.37a1.724 1.724 0 00-1.065-2.572c-1.756-.426-1.756-2.924 0-3.35a1.724 1.724 0 001.066-2.573c-.94-1.543.826-3.31 2.37-2.37.996.608 2.296.07 2.572-1.065z"
+              />
+              <path
+                strokeLinecap="round"
+                strokeLinejoin="round"
+                strokeWidth={1.8}
+                d="M15 12a3 3 0 11-6 0 3 3 0 016 0z"
+              />
+            </svg>
+          </button>
+        </Tooltip>
 
         {/* Collapse the sidebar — sits on the right, next to Settings. */}
-        <button
-          type="button"
-          onClick={hide}
-          className={ICON_BTN}
-          data-analytics-id="sidebar-header-collapse"
-          aria-label={t('chat.hideSidebar')}
-          title={t('chat.hideSidebar')}>
-          <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
-            <path
-              strokeLinecap="round"
-              strokeLinejoin="round"
-              strokeWidth={1.8}
-              d="M15 19l-7-7 7-7M20 5v14"
-            />
-          </svg>
-        </button>
+        <Tooltip label={t('chat.hideSidebar')}>
+          <button
+            type="button"
+            onClick={hide}
+            className={ICON_BTN}
+            data-analytics-id="sidebar-header-collapse"
+            aria-label={t('chat.hideSidebar')}>
+            <svg className="h-4 w-4" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+              <path
+                strokeLinecap="round"
+                strokeLinejoin="round"
+                strokeWidth={1.8}
+                d="M15 19l-7-7 7-7M20 5v14"
+              />
+            </svg>
+          </button>
+        </Tooltip>
       </div>
     </div>
   );
diff --git a/app/src/components/ui/Tooltip.test.tsx b/app/src/components/ui/Tooltip.test.tsx
new file mode 100644
index 000000000..4c5352b72
--- /dev/null
+++ b/app/src/components/ui/Tooltip.test.tsx
@@ -0,0 +1,175 @@
+import { act, fireEvent, render, screen } from '@testing-library/react';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import Tooltip from './Tooltip';
+
+describe('Tooltip', () => {
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.runOnlyPendingTimers();
+    vi.useRealTimers();
+  });
+
+  it('does not show the pill until the trigger is hovered past the delay', () => {
+    render(
+      <Tooltip label="Wallet" delayMs={300}>
+        <button type="button" aria-label="Wallet">
+          icon
+        </button>
+      </Tooltip>
+    );
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+
+    fireEvent.mouseEnter(screen.getByRole('button', { name: 'Wallet' }));
+    // Before the dwell elapses, nothing is shown.
+    act(() => {
+      vi.advanceTimersByTime(200);
+    });
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+
+    act(() => {
+      vi.advanceTimersByTime(100);
+    });
+    expect(screen.getByTestId('tooltip')).toHaveTextContent('Wallet');
+  });
+
+  it('hides the pill on mouse leave and cancels a pending show', () => {
+    render(
+      <Tooltip label="Settings">
+        <button type="button" aria-label="Settings">
+          icon
+        </button>
+      </Tooltip>
+    );
+    const btn = screen.getByRole('button', { name: 'Settings' });
+
+    fireEvent.mouseEnter(btn);
+    fireEvent.mouseLeave(btn);
+    act(() => {
+      vi.advanceTimersByTime(500);
+    });
+    // Leaving before the delay cancels the show entirely.
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+  });
+
+  it('shows on keyboard focus and hides on blur', () => {
+    render(
+      <Tooltip label="Home" delayMs={0}>
+        <button type="button" aria-label="Home">
+          icon
+        </button>
+      </Tooltip>
+    );
+    const btn = screen.getByRole('button', { name: 'Home' });
+
+    fireEvent.focus(btn);
+    act(() => {
+      vi.advanceTimersByTime(0);
+    });
+    expect(screen.getByTestId('tooltip')).toHaveTextContent('Home');
+
+    fireEvent.blur(btn);
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+  });
+
+  it('preserves the trigger’s own handlers', () => {
+    const onMouseEnter = vi.fn();
+    const onClick = vi.fn();
+    render(
+      <Tooltip label="Chat" delayMs={0}>
+        <button type="button" aria-label="Chat" onMouseEnter={onMouseEnter} onClick={onClick}>
+          icon
+        </button>
+      </Tooltip>
+    );
+    const btn = screen.getByRole('button', { name: 'Chat' });
+
+    fireEvent.mouseEnter(btn);
+    fireEvent.click(btn);
+    expect(onMouseEnter).toHaveBeenCalledTimes(1);
+    expect(onClick).toHaveBeenCalledTimes(1);
+  });
+
+  it('marks the pill aria-hidden so screen readers use the trigger label', () => {
+    render(
+      <Tooltip label="Connections" delayMs={0}>
+        <button type="button" aria-label="Connections">
+          icon
+        </button>
+      </Tooltip>
+    );
+    fireEvent.mouseEnter(screen.getByRole('button', { name: 'Connections' }));
+    act(() => {
+      vi.advanceTimersByTime(0);
+    });
+    expect(screen.getByTestId('tooltip')).toHaveAttribute('aria-hidden', 'true');
+  });
+
+  it.each([
+    ['right', 'translateY(-50%)'],
+    ['left', 'translate(-100%, -50%)'],
+    ['top', 'translate(-50%, -100%)'],
+    ['bottom', 'translate(-50%, 0)'],
+  ] as const)('positions the pill against the %s edge', (side, transform) => {
+    render(
+      <Tooltip label="Brain" side={side} delayMs={0}>
+        <button type="button" aria-label="Brain">
+          icon
+        </button>
+      </Tooltip>
+    );
+    fireEvent.mouseEnter(screen.getByRole('button', { name: 'Brain' }));
+    act(() => {
+      vi.advanceTimersByTime(0);
+    });
+    expect(screen.getByTestId('tooltip')).toHaveStyle({ transform });
+  });
+
+  it('renders an invalid (non-element) child as-is without a pill', () => {
+    render(<Tooltip label="Noop">{'just text' as never}</Tooltip>);
+    expect(screen.getByText('just text')).toBeInTheDocument();
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+  });
+
+  it('applies a native title fallback on the trigger (CEF-occlusion safety net)', () => {
+    render(
+      <Tooltip label="Wallet" delayMs={0}>
+        <button type="button" aria-label="Wallet">
+          icon
+        </button>
+      </Tooltip>
+    );
+    expect(screen.getByRole('button', { name: 'Wallet' })).toHaveAttribute('title', 'Wallet');
+  });
+
+  it('respects a trigger-supplied title over the label fallback', () => {
+    render(
+      <Tooltip label="Wallet" delayMs={0}>
+        <button type="button" aria-label="Wallet" title="Custom">
+          icon
+        </button>
+      </Tooltip>
+    );
+    expect(screen.getByRole('button', { name: 'Wallet' })).toHaveAttribute('title', 'Custom');
+  });
+
+  it('clears a pending show when the trigger unmounts mid-hover', () => {
+    const { unmount } = render(
+      <Tooltip label="Human" delayMs={300}>
+        <button type="button" aria-label="Human">
+          icon
+        </button>
+      </Tooltip>
+    );
+    fireEvent.mouseEnter(screen.getByRole('button', { name: 'Human' }));
+    unmount();
+    // The timer must not fire setState on the unmounted component.
+    act(() => {
+      vi.advanceTimersByTime(500);
+    });
+    expect(screen.queryByTestId('tooltip')).toBeNull();
+  });
+});
diff --git a/app/src/components/ui/Tooltip.tsx b/app/src/components/ui/Tooltip.tsx
new file mode 100644
index 000000000..8bb63d42e
--- /dev/null
+++ b/app/src/components/ui/Tooltip.tsx
@@ -0,0 +1,161 @@
+import debug from 'debug';
+import {
+  cloneElement,
+  type FocusEvent,
+  isValidElement,
+  type MouseEvent,
+  type ReactElement,
+  useCallback,
+  useEffect,
+  useRef,
+  useState,
+} from 'react';
+import { createPortal } from 'react-dom';
+
+const log = debug('ui:tooltip');
+
+/** Which edge of the trigger the tooltip floats from. Sidebar icons use `right`. */
+export type TooltipSide = 'right' | 'top' | 'bottom' | 'left';
+
+export interface TooltipProps {
+  /** Short, minimal label — e.g. "Wallet", "Settings". */
+  label: string;
+  /** Single focusable trigger (a button/anchor). Its hover/focus drives the tip. */
+  children: ReactElement;
+  /** Edge to float from. Defaults to `right` (best for a vertical sidebar rail). */
+  side?: TooltipSide;
+  /** Hover/focus dwell before showing, in ms. Keeps the tip from flickering. */
+  delayMs?: number;
+}
+
+/** Gap in px between the trigger and the tooltip pill. */
+const GAP = 8;
+
+interface Anchor {
+  top: number;
+  left: number;
+  side: TooltipSide;
+}
+
+function anchorFor(rect: DOMRect, side: TooltipSide): Anchor {
+  switch (side) {
+    case 'top':
+      return { top: rect.top - GAP, left: rect.left + rect.width / 2, side };
+    case 'bottom':
+      return { top: rect.bottom + GAP, left: rect.left + rect.width / 2, side };
+    case 'left':
+      return { top: rect.top + rect.height / 2, left: rect.left - GAP, side };
+    case 'right':
+    default:
+      return { top: rect.top + rect.height / 2, left: rect.right + GAP, side };
+  }
+}
+
+/** Maps the float edge to the transform that pins the pill against that edge. */
+const TRANSFORM: Record<TooltipSide, string> = {
+  right: 'translateY(-50%)',
+  left: 'translate(-100%, -50%)',
+  top: 'translate(-50%, -100%)',
+  bottom: 'translate(-50%, 0)',
+};
+
+/**
+ * Lightweight, dependency-free hover/focus tooltip for icon-only controls.
+ *
+ * Renders a styled pill into a body portal (so it escapes the sidebar's
+ * `overflow` clipping) positioned from the trigger's bounding rect. The pill
+ * gives fast (~`delayMs`), on-brand feedback that the native `title` attribute
+ * (lags ~1.5s, unstyled, easy to miss) cannot.
+ *
+ * The trigger also keeps a native `title={label}` fallback (unless it already
+ * sets one). This is deliberate: the pill lives in the HTML layer, but account
+ * webviews are native CEF views composited *above* HTML (see `Accounts.tsx` /
+ * `RootShellLayout.tsx`), so a pill that lands over an active webview is painted
+ * behind it. The OS-drawn `title` renders above everything and guarantees a
+ * label survives in that case. Pair with an `aria-label` on the trigger for
+ * screen readers (it takes precedence over `title`, so there's no double
+ * announcement); the pill itself is decorative (`aria-hidden`).
+ */
+export default function Tooltip({ label, children, side = 'right', delayMs = 300 }: TooltipProps) {
+  const [anchor, setAnchor] = useState<Anchor | null>(null);
+  const timerRef = useRef<ReturnType<typeof setTimeout> | null>(null);
+
+  const clearTimer = useCallback(() => {
+    if (timerRef.current) {
+      clearTimeout(timerRef.current);
+      timerRef.current = null;
+    }
+  }, []);
+
+  const show = useCallback(
+    (rect: DOMRect) => {
+      clearTimer();
+      timerRef.current = setTimeout(() => {
+        log('show', label);
+        setAnchor(anchorFor(rect, side));
+      }, delayMs);
+    },
+    [clearTimer, delayMs, label, side]
+  );
+
+  const hide = useCallback(() => {
+    clearTimer();
+    setAnchor(null);
+  }, [clearTimer]);
+
+  // Drop any pending show if the trigger unmounts mid-hover (e.g. navigation
+  // tears down the rail before mouseleave/blur fires).
+  useEffect(() => clearTimer, [clearTimer]);
+
+  if (!isValidElement(children)) {
+    log('children is not a valid element; rendering trigger as-is');
+    return children;
+  }
+
+  const triggerProps = children.props as {
+    title?: string;
+    onMouseEnter?: (e: MouseEvent<HTMLElement>) => void;
+    onMouseLeave?: (e: MouseEvent<HTMLElement>) => void;
+    onFocus?: (e: FocusEvent<HTMLElement>) => void;
+    onBlur?: (e: FocusEvent<HTMLElement>) => void;
+  };
+
+  const trigger = cloneElement(children, {
+    // Native `title` fallback for when the portal pill is occluded by a native
+    // CEF webview composited above the HTML layer. A trigger-supplied title wins.
+    title: triggerProps.title ?? label,
+    onMouseEnter: (e: MouseEvent<HTMLElement>) => {
+      show(e.currentTarget.getBoundingClientRect());
+      triggerProps.onMouseEnter?.(e);
+    },
+    onMouseLeave: (e: MouseEvent<HTMLElement>) => {
+      hide();
+      triggerProps.onMouseLeave?.(e);
+    },
+    onFocus: (e: FocusEvent<HTMLElement>) => {
+      show(e.currentTarget.getBoundingClientRect());
+      triggerProps.onFocus?.(e);
+    },
+    onBlur: (e: FocusEvent<HTMLElement>) => {
+      hide();
+      triggerProps.onBlur?.(e);
+    },
+  } as Partial<typeof children.props>);
+
+  return (
+    <>
+      {trigger}
+      {anchor &&
+        createPortal(
+          <div
+            data-testid="tooltip"
+            aria-hidden="true"
+            className="pointer-events-none fixed z-[9999] whitespace-nowrap rounded-md bg-stone-800 px-2 py-1 text-xs font-medium text-white shadow-md animate-fade-in dark:bg-neutral-700"
+            style={{ top: anchor.top, left: anchor.left, transform: TRANSFORM[anchor.side] }}>
+            {label}
+          </div>,
+          document.body
+        )}
+    </>
+  );
+}
diff --git a/app/src/components/ui/index.ts b/app/src/components/ui/index.ts
index 5f40f1dcd..e8c6f0561 100644
--- a/app/src/components/ui/index.ts
+++ b/app/src/components/ui/index.ts
@@ -7,6 +7,9 @@ export type { CardProps, CardVariant, CardPadding } from './Card';
 export { default as Input } from './Input';
 export type { InputProps, InputSize } from './Input';
 
+export { default as Tooltip } from './Tooltip';
+export type { TooltipProps, TooltipSide } from './Tooltip';
+
 export { Spinner, CheckIcon, CloseIcon, WarningIcon } from './icons';
 export { CenteredLoadingState, ErrorBanner, InlineLoadingStatus } from './LoadingState';
 export { ModalShell } from './ModalShell';