diff --git a/src/main/engine/MediaEngine.ts b/src/main/engine/MediaEngine.ts
index 2479dfb..30b371c 100644
--- a/src/main/engine/MediaEngine.ts
+++ b/src/main/engine/MediaEngine.ts
@@ -638,6 +638,96 @@ export class MediaEngine extends EventEmitter {
 
     await taskManager.runTask(task);
   }
+
+  /**
+   * Regenerate missing thumbnails for all image media.
+   * Useful for media imported externally without thumbnails.
+   */
+  async regenerateMissingThumbnails(): Promise<{ processed: number; generated: number; failed: number }> {
+    const result = { processed: 0, generated: 0, failed: 0 };
+
+    const task: Task<{ processed: number; generated: number; failed: number }> = {
+      id: uuidv4(),
+      name: 'Generate missing thumbnails',
+      execute: async (onProgress) => {
+        const db = getDatabase().getLocal();
+
+        onProgress(0, 'Finding images without thumbnails...');
+
+        // Get all image media for current project
+        const allMedia = await db
+          .select()
+          .from(media)
+          .where(eq(media.projectId, this.currentProjectId))
+          .all();
+
+        // Filter to images only (not SVG - they don't need thumbnails)
+        const imageMedia = allMedia.filter(
+          m => m.mimeType.startsWith('image/') && !m.mimeType.includes('svg')
+        );
+
+        if (imageMedia.length === 0) {
+          onProgress(100, 'No images found');
+          return result;
+        }
+
+        onProgress(5, `Checking ${imageMedia.length} images...`);
+
+        // Find which ones are missing thumbnails
+        const missingThumbnails: typeof imageMedia = [];
+        for (const item of imageMedia) {
+          const thumbnails = await this.getThumbnailPaths(item.id);
+          // Consider missing if any size is missing
+          if (!thumbnails.small || !thumbnails.medium || !thumbnails.large) {
+            missingThumbnails.push(item);
+          }
+        }
+
+        if (missingThumbnails.length === 0) {
+          onProgress(100, 'All thumbnails exist');
+          return result;
+        }
+
+        onProgress(10, `Generating thumbnails for ${missingThumbnails.length} images...`);
+
+        for (let i = 0; i < missingThumbnails.length; i++) {
+          const item = missingThumbnails[i];
+          result.processed++;
+
+          const progress = 10 + (90 * ((i + 1) / missingThumbnails.length));
+          onProgress(progress, `Processing ${i + 1}/${missingThumbnails.length}: ${item.originalName}`);
+
+          try {
+            // Verify the source file exists
+            await fs.access(item.filePath);
+            
+            const thumbnails = await this.generateThumbnails(item.id, item.filePath);
+            
+            // Check if thumbnails were actually generated
+            if (Object.keys(thumbnails).length > 0) {
+              result.generated++;
+            } else {
+              result.failed++;
+            }
+          } catch (error) {
+            console.error(`Failed to generate thumbnails for ${item.id}:`, error);
+            result.failed++;
+          }
+
+          // Yield to event loop periodically
+          if (i % 5 === 0) {
+            await new Promise(resolve => setImmediate(resolve));
+          }
+        }
+
+        onProgress(100, `Generated ${result.generated} thumbnails, ${result.failed} failed`);
+        this.emit('thumbnailsRegenerated', result);
+        return result;
+      },
+    };
+
+    return await taskManager.runTask(task);
+  }
 }
 
 // Singleton instance
diff --git a/src/main/ipc/handlers.ts b/src/main/ipc/handlers.ts
index 26b7e62..ea32814 100644
--- a/src/main/ipc/handlers.ts
+++ b/src/main/ipc/handlers.ts
@@ -327,6 +327,16 @@ export function registerIpcHandlers(): void {
     return null;
   });
 
+  ipcMain.handle('media:regenerateMissingThumbnails', async () => {
+    const projectEngine = getProjectEngine();
+    const project = await projectEngine.getActiveProject();
+    const engine = getMediaEngine();
+    if (project) {
+      engine.setProjectContext(project.id);
+    }
+    return engine.regenerateMissingThumbnails();
+  });
+
   // ============ Sync Handlers ============
 
   ipcMain.handle('sync:configure', async (_, config: SyncConfig) => {
diff --git a/src/main/preload.ts b/src/main/preload.ts
index ce72658..a85ca85 100644
--- a/src/main/preload.ts
+++ b/src/main/preload.ts
@@ -56,6 +56,7 @@ contextBridge.exposeInMainWorld('electronAPI', {
     rebuildFromFiles: () => ipcRenderer.invoke('media:rebuildFromFiles'),
     getThumbnail: (id: string, size?: 'small' | 'medium' | 'large') => ipcRenderer.invoke('media:getThumbnail', id, size),
     regenerateThumbnails: (id: string) => ipcRenderer.invoke('media:regenerateThumbnails', id),
+    regenerateMissingThumbnails: () => ipcRenderer.invoke('media:regenerateMissingThumbnails'),
   },
 
   // Sync
diff --git a/src/renderer/App.tsx b/src/renderer/App.tsx
index 2ae7b67..3f37a9e 100644
--- a/src/renderer/App.tsx
+++ b/src/renderer/App.tsx
@@ -342,6 +342,8 @@ const App: React.FC = () => {
         // Fire and forget - the handlers return immediately now
         window.electronAPI?.posts.rebuildFromFiles();
         window.electronAPI?.media.rebuildFromFiles();
+        // Also regenerate missing thumbnails after media rebuild
+        window.electronAPI?.media.regenerateMissingThumbnails();
       }) || (() => {})
     );
 
diff --git a/src/renderer/components/SettingsView/SettingsView.tsx b/src/renderer/components/SettingsView/SettingsView.tsx
index 7aedbf8..ddf6b17 100644
--- a/src/renderer/components/SettingsView/SettingsView.tsx
+++ b/src/renderer/components/SettingsView/SettingsView.tsx
@@ -939,6 +939,35 @@ export const SettingsView: React.FC = () => {
             Rebuild Links
           </button>
         </SettingRow>
+
+        <SettingRow
+          id="regenerate-thumbnails"
+          label="Regenerate Thumbnails"
+          description="Generate missing thumbnails for all images. Useful after importing media externally."
+        >
+          <button
+            className="secondary"
+            onClick={async () => {
+              showToast.loading('Generating thumbnails...');
+              try {
+                const result = await window.electronAPI?.media.regenerateMissingThumbnails();
+                showToast.dismiss();
+                if (result && result.generated > 0) {
+                  showToast.success(`Generated ${result.generated} thumbnails`);
+                } else if (result && result.processed === 0) {
+                  showToast.success('All thumbnails already exist');
+                } else {
+                  showToast.success('Thumbnail generation complete');
+                }
+              } catch {
+                showToast.dismiss();
+                showToast.error('Failed to generate thumbnails');
+              }
+            }}
+          >
+            Generate Thumbnails
+          </button>
+        </SettingRow>
       </SettingSection>
 
       <SettingSection
diff --git a/src/renderer/types/electron.d.ts b/src/renderer/types/electron.d.ts
index 30e1b6e..d5cded1 100644
--- a/src/renderer/types/electron.d.ts
+++ b/src/renderer/types/electron.d.ts
@@ -272,8 +272,13 @@ export interface ElectronAPI {
     update: (id: string, data: Partial<MediaData>) => Promise<MediaData | null>;
     delete: (id: string) => Promise<boolean>;
     get: (id: string) => Promise<MediaData | null>;
+    getUrl: (id: string) => Promise<string | null>;
+    getFilePath: (id: string) => Promise<string | null>;
     getAll: () => Promise<MediaData[]>;
     rebuildFromFiles: () => Promise<void>;
+    getThumbnail: (id: string, size?: 'small' | 'medium' | 'large') => Promise<string | null>;
+    regenerateThumbnails: (id: string) => Promise<Record<string, string> | null>;
+    regenerateMissingThumbnails: () => Promise<{ processed: number; generated: number; failed: number }>;
   };
   sync: {
     configure: (config: SyncConfig) => Promise<void>;