diff --git a/src/main/settings.ts b/src/main/settings.ts
index 82cd0cc3d..8f24c92cf 100644
--- a/src/main/settings.ts
+++ b/src/main/settings.ts
@@ -70,6 +70,7 @@ export interface InterfaceSettings {
   showResourceMonitor?: boolean;
   theme?: 'light' | 'dark' | 'dark-black' | 'system';
   taskHoverAction?: 'delete' | 'archive';
+  expandCommitDetail?: boolean;
 }
 
 /**
@@ -205,6 +206,7 @@ const DEFAULT_SETTINGS: AppSettings = {
     showResourceMonitor: false,
     theme: 'system',
     taskHoverAction: 'delete',
+    expandCommitDetail: false,
   },
   providerConfigs: {},
   terminal: {
@@ -549,6 +551,9 @@ export function normalizeSettings(input: AppSettings): AppSettings {
       ? iface.theme
       : DEFAULT_SETTINGS.interface!.theme,
     taskHoverAction: iface?.taskHoverAction === 'archive' ? 'archive' : 'delete',
+    expandCommitDetail: Boolean(
+      iface?.expandCommitDetail ?? DEFAULT_SETTINGS.interface!.expandCommitDetail
+    ),
   };
 
   // Provider custom configs
diff --git a/src/renderer/components/CommitDetailSettingsCard.tsx b/src/renderer/components/CommitDetailSettingsCard.tsx
new file mode 100644
index 000000000..8a051e9bc
--- /dev/null
+++ b/src/renderer/components/CommitDetailSettingsCard.tsx
@@ -0,0 +1,32 @@
+import React from 'react';
+import { Switch } from './ui/switch';
+import { useAppSettings } from '@/contexts/AppSettingsProvider';
+
+const CommitDetailSettingsCard: React.FC = () => {
+  const { settings, updateSettings, isLoading: loading } = useAppSettings();
+
+  const expandCommitDetail = settings?.interface?.expandCommitDetail ?? false;
+
+  return (
+    <div className="flex items-center justify-between gap-4">
+      <div className="flex flex-1 flex-col gap-0.5">
+        <span className="text-sm font-medium text-foreground">
+          Expand commit details by default
+        </span>
+        <span className="text-sm text-muted-foreground">
+          Automatically show the full commit message and author when selecting a commit in the
+          History tab
+        </span>
+      </div>
+      <Switch
+        checked={expandCommitDetail}
+        disabled={loading}
+        onCheckedChange={(checked) =>
+          updateSettings({ interface: { expandCommitDetail: checked } })
+        }
+      />
+    </div>
+  );
+};
+
+export default CommitDetailSettingsCard;
diff --git a/src/renderer/components/SettingsPage.tsx b/src/renderer/components/SettingsPage.tsx
index 293cb280d..8fd3e142b 100644
--- a/src/renderer/components/SettingsPage.tsx
+++ b/src/renderer/components/SettingsPage.tsx
@@ -28,6 +28,7 @@ import TerminalSettingsCard from './TerminalSettingsCard';
 import HiddenToolsSettingsCard from './HiddenToolsSettingsCard';
 import ReviewAgentSettingsCard from './ReviewAgentSettingsCard';
 import ResourceMonitorSettingsCard from './ResourceMonitorSettingsCard';
+import CommitDetailSettingsCard from './CommitDetailSettingsCard';
 import { AccountTab } from './settings/AccountTab';
 import { WorkspaceProviderInfoCard } from './WorkspaceProviderInfoCard';
 import { useTaskSettings } from '../hooks/useTaskSettings';
@@ -268,6 +269,7 @@ export const SettingsPage: React.FC<SettingsPageProps> = ({ initialTab, onClose
               <RightSidebarSettingsCard />
               <BrowserPreviewSettingsCard />
               <TaskHoverActionCard />
+              <CommitDetailSettingsCard />
             </div>
           ),
         },
diff --git a/src/renderer/components/diff-viewer/HistoryTab.tsx b/src/renderer/components/diff-viewer/HistoryTab.tsx
index d6c65a634..271ee1116 100644
--- a/src/renderer/components/diff-viewer/HistoryTab.tsx
+++ b/src/renderer/components/diff-viewer/HistoryTab.tsx
@@ -6,6 +6,8 @@ import { CommitFileList } from './CommitFileList';
 import { CommitFileDiffView } from './CommitFileDiffView';
 import { DiffToolbar } from './DiffToolbar';
 import { ResizablePanelGroup, ResizablePanel, ResizableHandle } from '../ui/resizable';
+import { useAppSettings } from '@/contexts/AppSettingsProvider';
+import { cn } from '@/lib/utils';
 
 interface HistoryTabProps {
   taskPath?: string;
@@ -27,6 +29,8 @@ export const HistoryTab: React.FC<HistoryTabProps> = ({
   const [diffStyle, setDiffStyle] = useState<'unified' | 'split'>(
     () => (localStorage.getItem('diffViewer:diffStyle') as 'unified' | 'split') || 'unified'
   );
+  const { settings } = useAppSettings();
+  const expandByDefault = settings?.interface?.expandCommitDetail ?? false;
   const [detailExpanded, setDetailExpanded] = useState(false);
   const [copied, setCopied] = useState(false);
 
@@ -39,7 +43,7 @@ export const HistoryTab: React.FC<HistoryTabProps> = ({
     if (commit.hash === selectedCommit?.hash) return;
     setSelectedCommit(commit);
     setSelectedFile(null);
-    setDetailExpanded(false);
+    setDetailExpanded(expandByDefault);
     setCopied(false);
   };
 
@@ -99,7 +103,12 @@ export const HistoryTab: React.FC<HistoryTabProps> = ({
               {/* Commit message detail */}
               <div className="border-b border-border px-3 py-2">
                 <div className="flex items-center gap-1">
-                  <div className="min-w-0 flex-1 truncate text-sm font-medium leading-snug">
+                  <div
+                    className={cn(
+                      'min-w-0 flex-1 text-sm font-medium leading-snug',
+                      !detailExpanded && 'truncate'
+                    )}
+                  >
                     {selectedCommit.subject}
                   </div>
                   {hasExpandableContent && (
diff --git a/src/test/main/settings.test.ts b/src/test/main/settings.test.ts
index 5456eeab2..0463f7c33 100644
--- a/src/test/main/settings.test.ts
+++ b/src/test/main/settings.test.ts
@@ -283,3 +283,25 @@ describe('normalizeSettings – terminal settings', () => {
     expect(result.terminal?.macOptionIsMeta).toBe(true);
   });
 });
+
+describe('normalizeSettings – expandCommitDetail', () => {
+  it('defaults expandCommitDetail to false when not set', () => {
+    const result = normalizeSettings(makeSettings());
+    expect(result.interface?.expandCommitDetail).toBe(false);
+  });
+
+  it('preserves expandCommitDetail: true', () => {
+    const result = normalizeSettings(makeSettings({ interface: { expandCommitDetail: true } }));
+    expect(result.interface?.expandCommitDetail).toBe(true);
+  });
+
+  it('preserves expandCommitDetail: false', () => {
+    const result = normalizeSettings(makeSettings({ interface: { expandCommitDetail: false } }));
+    expect(result.interface?.expandCommitDetail).toBe(false);
+  });
+
+  it('coerces missing value inside interface to false', () => {
+    const result = normalizeSettings(makeSettings({ interface: {} }));
+    expect(result.interface?.expandCommitDetail).toBe(false);
+  });
+});
diff --git a/src/test/renderer/CommitDetailSettingsCard.component.test.tsx b/src/test/renderer/CommitDetailSettingsCard.component.test.tsx
new file mode 100644
index 000000000..b620ce7dc
--- /dev/null
+++ b/src/test/renderer/CommitDetailSettingsCard.component.test.tsx
@@ -0,0 +1,51 @@
+import { render, screen, fireEvent } from '@testing-library/react';
+import { describe, expect, it, vi } from 'vitest';
+import { useAppSettings } from '@/contexts/AppSettingsProvider';
+import CommitDetailSettingsCard from '../../renderer/components/CommitDetailSettingsCard';
+
+vi.mock('@/contexts/AppSettingsProvider', () => ({
+  useAppSettings: vi.fn(),
+}));
+
+function setup(expandCommitDetail = false) {
+  const updateSettings = vi.fn();
+  vi.mocked(useAppSettings).mockReturnValue({
+    settings: {
+      interface: { expandCommitDetail },
+    } as unknown as ReturnType<typeof useAppSettings>['settings'],
+    isLoading: false,
+    isSaving: false,
+    updateSettings,
+  });
+  render(<CommitDetailSettingsCard />);
+  return { updateSettings };
+}
+
+describe('CommitDetailSettingsCard', () => {
+  it('renders the toggle label', () => {
+    setup();
+    expect(screen.getByText('Expand commit details by default')).toBeInTheDocument();
+  });
+
+  it('is unchecked when expandCommitDetail is false', () => {
+    setup(false);
+    expect(screen.getByRole('switch')).toHaveAttribute('data-state', 'unchecked');
+  });
+
+  it('is checked when expandCommitDetail is true', () => {
+    setup(true);
+    expect(screen.getByRole('switch')).toHaveAttribute('data-state', 'checked');
+  });
+
+  it('calls updateSettings with true when toggled on', () => {
+    const { updateSettings } = setup(false);
+    fireEvent.click(screen.getByRole('switch'));
+    expect(updateSettings).toHaveBeenCalledWith({ interface: { expandCommitDetail: true } });
+  });
+
+  it('calls updateSettings with false when toggled off', () => {
+    const { updateSettings } = setup(true);
+    fireEvent.click(screen.getByRole('switch'));
+    expect(updateSettings).toHaveBeenCalledWith({ interface: { expandCommitDetail: false } });
+  });
+});