diff --git a/apps/dashboard/src/features/settings/settings-model.ts b/apps/dashboard/src/features/settings/settings-model.ts
index acf6cc8..48430e7 100644
--- a/apps/dashboard/src/features/settings/settings-model.ts
+++ b/apps/dashboard/src/features/settings/settings-model.ts
@@ -9,6 +9,7 @@ import {
 
 export interface SubredditDraft {
   name: string;
+  enabled: boolean;
   type: 'image' | 'chat';
   weight: string;
   tone: z.infer<typeof ToneKeySchema>;
@@ -67,6 +68,7 @@ export function createSettingsDraft(config: ConfigResponse): SettingsDraft {
     recentWindowMinutes: String(config.reddit.recentWindowMinutes),
     subreddits: config.subreddits.map((subreddit) => ({
       name: subreddit.name,
+      enabled: subreddit.enabled,
       type: subreddit.type,
       weight: subreddit.weight === undefined ? '' : String(subreddit.weight),
       tone: subreddit.tone,
@@ -112,6 +114,7 @@ export function validateSettingsDraft(draft: SettingsDraft): SettingsValidationR
     recentWindowMinutes: Number(draft.recentWindowMinutes),
     subreddits: draft.subreddits.map((subreddit) => ({
       name: subreddit.name.trim(),
+      enabled: subreddit.enabled,
       type: subreddit.type,
       weight: subreddit.weight.trim() === '' ? undefined : Number(subreddit.weight),
       tone: subreddit.tone,
diff --git a/apps/dashboard/src/features/settings/settings-sections.tsx b/apps/dashboard/src/features/settings/settings-sections.tsx
index 45ea5d4..905beba 100644
--- a/apps/dashboard/src/features/settings/settings-sections.tsx
+++ b/apps/dashboard/src/features/settings/settings-sections.tsx
@@ -122,7 +122,7 @@ export function BehaviourSection({ config, draft, errors, onChange }: SectionPro
             ...draft,
             subreddits: [
               ...draft.subreddits,
-              { name: '', type: 'image', weight: '1', tone: 'default', scripted: '' },
+              { name: '', enabled: true, type: 'image', weight: '1', tone: 'default', scripted: '' },
             ],
           })}
           type="button"
@@ -157,6 +157,15 @@ export function BehaviourSection({ config, draft, errors, onChange }: SectionPro
                 <option value="image">Image</option><option value="chat">Chat</option>
               </select>
             </label>
+            <label className="toggle-field">
+              <input
+                aria-label={`Subreddit ${index + 1} enabled`}
+                checked={subreddit.enabled}
+                onChange={(event) => onChange(updateSubreddit(draft, index, { ...subreddit, enabled: event.target.checked }))}
+                type="checkbox"
+              />
+              <span><strong>Enabled</strong><small>Disabled subreddits are not polled.</small></span>
+            </label>
             <label className="settings-field">
               <span>Weight</span>
               <input
diff --git a/packages/api-contracts/src/config.ts b/packages/api-contracts/src/config.ts
index bd55049..3bd3d25 100644
--- a/packages/api-contracts/src/config.ts
+++ b/packages/api-contracts/src/config.ts
@@ -27,6 +27,7 @@ export const RuntimeConfigSchema = z.strictObject({
 });
 export const SubredditConfigSchema = z.strictObject({
   name: z.string(),
+  enabled: z.boolean().default(true),
   type: z.union([z.literal('image'), z.literal('chat')]),
   weight: z.number().optional(),
   tone: ToneKeySchema,
diff --git a/src/bootstrap.ts b/src/bootstrap.ts
index 9de0e05..f308945 100644
--- a/src/bootstrap.ts
+++ b/src/bootstrap.ts
@@ -49,6 +49,7 @@ import { RedditAccountRuntimeManager } from './services/reddit-account-runtime.j
 import { createConcreteRedditAccountRuntimeFactory } from './services/reddit-account-runtime-builder.js';
 import { importLegacyAccountContent } from './database/legacy-content-import.js';
 import { RecipientDeduplicator } from './services/recipient-deduplicator.js';
+import { createConfigBackedSubredditPollingControl } from './services/subreddit-polling-control.js';
 
 export interface AppContainer {
   config: Config;
@@ -168,7 +169,10 @@ export async function bootstrap(
 
   // AI + services
   const aiClient = new OpenRouterClient(config, logger);
-  const monitorService = new MonitorService(redditApi, postsRepo, recipientDeduplicator, config, logger);
+  const monitorService = new MonitorService(
+    redditApi, postsRepo, recipientDeduplicator, config, logger, 1000,
+    createConfigBackedSubredditPollingControl(config, new ConfigStore(db), logger),
+  );
   const processorService = new ProcessorService(redditApi, aiClient, config, logger);
   const strategySelector = new StrategySelector(config, messagesRepo, logger);
   processorService.setStrategySelector(strategySelector);
diff --git a/src/config/index.ts b/src/config/index.ts
index 4452f8d..844e3d0 100644
--- a/src/config/index.ts
+++ b/src/config/index.ts
@@ -9,6 +9,7 @@ dotenv.config();
 
 export const SubredditConfigSchema = z.object({
   name: z.string(),
+  enabled: z.boolean().default(true),
   type: z.enum(['image', 'chat']).default('image'),
   weight: z.number().positive().optional(),
   tone: z.enum(TONE_KEYS).default('default'),
diff --git a/src/reddit/api.ts b/src/reddit/api.ts
index 66abb7c..43d11a0 100644
--- a/src/reddit/api.ts
+++ b/src/reddit/api.ts
@@ -24,6 +24,14 @@ export class RedditAccessDeniedError extends Error {
   }
 }
 
+/** Reddit confirms the community listing is gone and must no longer be polled. */
+export class RedditSubredditUnavailableError extends Error {
+  constructor(public readonly subreddit: string) {
+    super(`Reddit reports that r/${subreddit} is unavailable (HTTP 404)`);
+    this.name = 'RedditSubredditUnavailableError';
+  }
+}
+
 function getRateLimitDelayMs(headers: unknown): number {
   if (!headers || typeof headers !== 'object') return 60_000;
 
@@ -198,8 +206,7 @@ export class RedditApiClient {
     } catch (error) {
       if (axios.isAxiosError(error)) {
         if (error.response?.status === 404) {
-          this.logger.warn(`Subreddit r/${subreddit} not found`);
-          return [];
+          throw new RedditSubredditUnavailableError(subreddit);
         }
         if (error.response?.status === 403) {
           this.consecutiveListing403s += 1;
diff --git a/src/services/monitor.ts b/src/services/monitor.ts
index 160daf2..7148c9a 100644
--- a/src/services/monitor.ts
+++ b/src/services/monitor.ts
@@ -1,4 +1,9 @@
-import { RedditRateLimitError, type RedditApiClient, type RedditPost } from '../reddit/api.js';
+import {
+  RedditRateLimitError,
+  RedditSubredditUnavailableError,
+  type RedditApiClient,
+  type RedditPost,
+} from '../reddit/api.js';
 import type { PostsRepository } from '../database/repositories.js';
 import type { Config } from '../config/index.js';
 import type { Logger } from '../utils/logger.js';
@@ -17,6 +22,12 @@ interface ListingScreeningSummary {
   deferredReason: 'selected-recent-candidate' | 'older-than-fallback' | null;
 }
 
+/** Coordinates permanent polling disablement across account runtimes. */
+export interface SubredditPollingControl {
+  disableUnavailableSubreddit(subreddit: string): void;
+  isSubredditEnabled(subreddit: string): boolean;
+}
+
 export class MonitorService {
   // Flips on each call so that when both pools have candidates the bot
   // alternates between image and chat instead of always favouring whichever
@@ -30,6 +41,7 @@ export class MonitorService {
     private config: Config,
     private logger: Logger,
     private delayBetweenFetchesMs: number = 1000,
+    private readonly pollingControl?: SubredditPollingControl,
   ) { }
 
   async getUnprocessedPosts(): Promise<RedditPost[]> {
@@ -151,6 +163,11 @@ export class MonitorService {
         }
       } catch (error) {
         if (error instanceof RedditRateLimitError) throw error;
+        if (error instanceof RedditSubredditUnavailableError) {
+          this.pollingControl?.disableUnavailableSubreddit(subreddit.name);
+          this.logger.warn(`Disabled r/${subreddit.name}: Reddit returned HTTP 404`);
+          continue;
+        }
 
         const errorMessage = error instanceof Error ? error.message : String(error);
         this.logger.error(`Failed to fetch posts from r/${subreddit.name}: ${errorMessage}`);
@@ -182,10 +199,10 @@ export class MonitorService {
    */
   private buildCheckOrder(): Config['reddit']['subreddits'] {
     const images = this.weightedShuffle(
-      this.config.reddit.subreddits.filter((s) => s.type === 'image'),
+      this.config.reddit.subreddits.filter((s) => s.type === 'image' && this.isSubredditEnabled(s.name)),
     );
     const chats = this.weightedShuffle(
-      this.config.reddit.subreddits.filter((s) => s.type === 'chat'),
+      this.config.reddit.subreddits.filter((s) => s.type === 'chat' && this.isSubredditEnabled(s.name)),
     );
 
     const [a, b] = this.chatGoesFirst ? [chats, images] : [images, chats];
@@ -200,6 +217,11 @@ export class MonitorService {
     return out;
   }
 
+  private isSubredditEnabled(subreddit: string): boolean {
+    const local = this.config.reddit.subreddits.find((entry) => entry.name.toLowerCase() === subreddit.toLowerCase());
+    return local?.enabled !== false && (this.pollingControl?.isSubredditEnabled(subreddit) ?? true);
+  }
+
   // Weighted random ordering (Efraimidis–Spirakis): key = random^(1/weight),
   // sorted descending. Heavier-weighted subs are more likely to land earlier
   // each cycle, while every sub still has a non-zero chance of any position.
diff --git a/src/services/reddit-account-runtime-builder.ts b/src/services/reddit-account-runtime-builder.ts
index 96aceaf..b0b5a6d 100644
--- a/src/services/reddit-account-runtime-builder.ts
+++ b/src/services/reddit-account-runtime-builder.ts
@@ -39,6 +39,8 @@ import {
   type VerifiedAccountSession,
 } from './reddit-account-runtime.js';
 import { RecipientDeduplicator } from './recipient-deduplicator.js';
+import { ConfigStore } from '../config/persistence.js';
+import { createConfigBackedSubredditPollingControl } from './subreddit-polling-control.js';
 
 export interface ConcreteRuntimeFactoryOptions {
   config: Config;
@@ -116,6 +118,7 @@ async function buildRuntime(
     const aiClient = new OpenRouterClient(accountConfig, logger);
     const monitorService = new MonitorService(
       redditApi, postsRepo, recipientDeduplicator, accountConfig, logger,
+      1000, createConfigBackedSubredditPollingControl(config, new ConfigStore(db), logger),
     );
     const processorService = new ProcessorService(redditApi, aiClient, accountConfig, logger);
     processorService.setStrategySelector(new StrategySelector(accountConfig, messagesRepo, logger));
diff --git a/src/services/subreddit-polling-control.ts b/src/services/subreddit-polling-control.ts
new file mode 100644
index 0000000..7eb69fd
--- /dev/null
+++ b/src/services/subreddit-polling-control.ts
@@ -0,0 +1,25 @@
+import type { Config } from '../config/index.js';
+import type { ConfigPersistence } from '../config/index.js';
+import type { Logger } from '../utils/logger.js';
+import type { SubredditPollingControl } from './monitor.js';
+
+/** Persists a terminal Reddit listing failure so every account stops polling it. */
+export function createConfigBackedSubredditPollingControl(
+  config: Config,
+  configStore: ConfigPersistence,
+  logger: Logger,
+): SubredditPollingControl {
+  return {
+    disableUnavailableSubreddit(subreddit: string): void {
+      const entry = config.reddit.subreddits.find((candidate) => candidate.name.toLowerCase() === subreddit.toLowerCase());
+      if (!entry || entry.enabled === false) return;
+
+      entry.enabled = false;
+      configStore.save(config);
+      logger.warn(`Persisted disabled status for unavailable subreddit r/${entry.name}`);
+    },
+    isSubredditEnabled(subreddit: string): boolean {
+      return config.reddit.subreddits.find((entry) => entry.name.toLowerCase() === subreddit.toLowerCase())?.enabled !== false;
+    },
+  };
+}
diff --git a/tests/config.test.ts b/tests/config.test.ts
index 2e34d5d..02fc847 100644
--- a/tests/config.test.ts
+++ b/tests/config.test.ts
@@ -49,6 +49,12 @@ describe('ConfigSchema', () => {
       }
     });
 
+    it('enables subreddits by default', () => {
+      const result = ConfigSchema.safeParse(minimalConfig({ reddit: { subreddits: ['test'] } }));
+      expect(result.success).toBe(true);
+      if (result.success) expect(result.data.reddit.subreddits[0].enabled).toBe(true);
+    });
+
     it('accepts valid tone values', () => {
       for (const tone of ['default', 'dominant', 'submissive', 'playful', 'direct', 'gentle', 'kink-friendly', 'teasing']) {
         const result = ConfigSchema.safeParse({
@@ -344,7 +350,7 @@ openrouter:
 `);
 
 const config = loadConfig();
-    expect(config.reddit.subreddits).toEqual([{ name: 'test-sub', type: 'image', tone: 'default' }]);
+    expect(config.reddit.subreddits).toEqual([{ name: 'test-sub', enabled: true, type: 'image', tone: 'default' }]);
     expect(config.reddit.pollIntervalMs).toBe(5000);
     expect(config.openrouter.apiKey).toBe('yaml-key');
   });
diff --git a/tests/monitor.test.ts b/tests/monitor.test.ts
index 36bd83d..3dc63f3 100644
--- a/tests/monitor.test.ts
+++ b/tests/monitor.test.ts
@@ -1,6 +1,11 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest';
 import { MonitorService } from '../src/services/monitor.js';
-import { RedditRateLimitError, type RedditApiClient, type RedditPost } from '../src/reddit/api.js';
+import {
+  RedditRateLimitError,
+  RedditSubredditUnavailableError,
+  type RedditApiClient,
+  type RedditPost,
+} from '../src/reddit/api.js';
 import type { PostsRepository, MessagesRepository } from '../src/database/repositories.js';
 import { createMockLogger } from '../tests/mockLogger.js';
 import { getTestConfig } from '../tests/testUtils.js';
@@ -87,6 +92,25 @@ describe('MonitorService', () => {
     expect(result.length).toBe(0);
   });
 
+  it('disables a subreddit when Reddit returns a terminal listing 404', async () => {
+    const redditApi = createMockRedditApi();
+    vi.mocked(redditApi.getNewPosts).mockRejectedValueOnce(new RedditSubredditUnavailableError('banned-sub'));
+    const pollingControl = {
+      disableUnavailableSubreddit: vi.fn(),
+      isSubredditEnabled: vi.fn(() => true),
+    };
+    const config = getTestConfig({ reddit: { subreddits: [{ name: 'banned-sub', type: 'image' }] } });
+    monitor = new MonitorService(
+      redditApi, createMockPostsRepo(), createMockMessagesRepo(), config, logger, 0, pollingControl,
+    );
+
+    await expect(monitor.getUnprocessedPosts()).resolves.toEqual([]);
+    expect(pollingControl.disableUnavailableSubreddit).toHaveBeenCalledWith('banned-sub');
+    expect(logger.logs).toContainEqual(expect.objectContaining({
+      level: 'warn', message: expect.stringContaining('Disabled r/banned-sub: Reddit returned HTTP 404'),
+    }));
+  });
+
   it('uses shared post history so another account cannot rediscover a post', async () => {
     const post: RedditPost = {
       id: 't3_shared', subreddit: 'sub1', author: 'user1', title: 'Post',
diff --git a/tests/reddit-api.test.ts b/tests/reddit-api.test.ts
index a9b77be..aecce95 100644
--- a/tests/reddit-api.test.ts
+++ b/tests/reddit-api.test.ts
@@ -480,14 +480,29 @@ describe('RedditApiClient', () => {
   });
 
   describe('getNewPosts', () => {
-    it('returns empty array for 404 subreddit', async () => {
+    it('throws a permanent-disable signal for a plain 404 subreddit', async () => {
       const error = { isAxiosError: true, response: { status: 404 } };
       const mockAxios = { get: vi.fn().mockRejectedValue(error) };
       vi.mocked(axios.create).mockReturnValue(mockAxios as any);
 
       const client2 = new RedditApiClient(getTestConfig(), logger);
-      const result = await client2.getNewPosts('nonexistent');
-      expect(result).toEqual([]);
+      await expect(client2.getNewPosts('nonexistent')).rejects.toMatchObject({
+        name: 'RedditSubredditUnavailableError', subreddit: 'nonexistent',
+      });
+    });
+
+    it('throws the same permanent-disable signal for Reddit banned responses', async () => {
+      const error = {
+        isAxiosError: true,
+        response: { status: 404, data: { reason: 'banned', message: 'Not Found', error: 404 } },
+      };
+      const mockAxios = { get: vi.fn().mockRejectedValue(error) };
+      vi.mocked(axios.create).mockReturnValue(mockAxios as unknown as AxiosInstance);
+
+      const client2 = new RedditApiClient(getTestConfig(), logger);
+      await expect(client2.getNewPosts('banned-sub')).rejects.toMatchObject({
+        name: 'RedditSubredditUnavailableError', subreddit: 'banned-sub',
+      });
     });
 
     it('returns empty array and explains an initial 403 access denial', async () => {
diff --git a/tests/subreddit-polling-control.test.ts b/tests/subreddit-polling-control.test.ts
new file mode 100644
index 0000000..822358a
--- /dev/null
+++ b/tests/subreddit-polling-control.test.ts
@@ -0,0 +1,21 @@
+import { describe, expect, it, vi } from 'vitest';
+import { createConfigBackedSubredditPollingControl } from '../src/services/subreddit-polling-control.js';
+import { getTestConfig } from './testUtils.js';
+import { createMockLogger } from './mockLogger.js';
+
+describe('config-backed subreddit polling control', () => {
+  it('disables and persists only the matched subreddit', () => {
+    const config = getTestConfig({ reddit: { subreddits: [{ name: 'gone', type: 'image' }, { name: 'active', type: 'chat' }] } });
+    const store = { load: vi.fn(), save: vi.fn() };
+    const control = createConfigBackedSubredditPollingControl(config, store, createMockLogger());
+
+    control.disableUnavailableSubreddit('GONE');
+
+    expect(config.reddit.subreddits).toEqual([
+      expect.objectContaining({ name: 'gone', enabled: false }),
+      expect.objectContaining({ name: 'active' }),
+    ]);
+    expect(store.save).toHaveBeenCalledWith(config);
+    expect(control.isSubredditEnabled('gone')).toBe(false);
+  });
+});