diff --git a/packages/catalyst/src/cli/commands/deploy.spec.ts b/packages/catalyst/src/cli/commands/deploy.spec.ts
index e15b8a5348..db0a4dec4a 100644
--- a/packages/catalyst/src/cli/commands/deploy.spec.ts
+++ b/packages/catalyst/src/cli/commands/deploy.spec.ts
@@ -561,3 +561,84 @@ describe('--prebuilt flag', () => {
     await emptyDistCleanup();
   });
 });
+
+describe('--update-site-url', () => {
+  const channelId = 7;
+
+  function deployArgs(extra: string[] = []) {
+    return [
+      'node',
+      'catalyst',
+      'deploy',
+      '--store-hash',
+      storeHash,
+      '--access-token',
+      accessToken,
+      '--api-host',
+      apiHost,
+      '--project-uuid',
+      projectUuid,
+      '--prebuilt',
+      ...extra,
+    ];
+  }
+
+  test('PUTs the deployment URL to the given channel', async () => {
+    let putBody: unknown;
+    let receivedChannelId: string | undefined;
+
+    server.use(
+      http.put(
+        'https://:apiHost/stores/:storeHash/v3/channels/:channelId/site',
+        async ({ request, params }) => {
+          putBody = await request.json();
+          receivedChannelId = String(params.channelId);
+
+          return HttpResponse.json({
+            data: { id: 1, url: 'https://example.com', channel_id: channelId },
+          });
+        },
+      ),
+    );
+
+    await program.parseAsync(deployArgs(['--update-site-url', String(channelId)]));
+
+    expect(receivedChannelId).toBe(String(channelId));
+    expect(putBody).toEqual({ url: 'https://example.com' });
+    expect(consola.success).toHaveBeenCalledWith(
+      `Updated channel ${channelId} site URL to https://example.com.`,
+    );
+  });
+
+  test('does not call the channel site API when the flag is omitted', async () => {
+    let putCalled = false;
+
+    server.use(
+      http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () => {
+        putCalled = true;
+
+        return HttpResponse.json({}, { status: 200 });
+      }),
+    );
+
+    await program.parseAsync(deployArgs());
+
+    expect(putCalled).toBe(false);
+    expect(consola.success).not.toHaveBeenCalledWith(expect.stringContaining('Updated channel'));
+  });
+
+  test('soft-fails with a warning when the update API returns an error', async () => {
+    server.use(
+      http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () =>
+        HttpResponse.json({}, { status: 401 }),
+      ),
+    );
+
+    await program.parseAsync(deployArgs(['--update-site-url', String(channelId)]));
+
+    expect(consola.warn).toHaveBeenCalledWith(
+      expect.stringContaining('Failed to update channel site URL'),
+    );
+    expect(consola.info).toHaveBeenCalledWith(expect.stringContaining('catalyst auth login'));
+  });
+});
diff --git a/packages/catalyst/src/cli/commands/deploy.ts b/packages/catalyst/src/cli/commands/deploy.ts
index 482d06cfef..3f4ebd01b6 100644
--- a/packages/catalyst/src/cli/commands/deploy.ts
+++ b/packages/catalyst/src/cli/commands/deploy.ts
@@ -6,6 +6,7 @@ import { join } from 'node:path';
 import yoctoSpinner from 'yocto-spinner';
 import { z } from 'zod';
 
+import { updateChannelSiteUrl } from '../lib/channels';
 import { getDeploymentErrorMessage } from '../lib/deployment-errors';
 import { consola } from '../lib/logger';
 import { getProjectConfig } from '../lib/project-config';
@@ -66,6 +67,10 @@ const DeploymentStatusSchema = z.object({
     })
     .nullable(),
   deployment_url: z.string().nullable(),
+  // TODO: deployment_url is being deprecated in favor of deployment_hostnames (string[]).
+  // When the backend rolls it out, switch over here and update the consumer below to pick
+  // the primary hostname.
+  // deployment_hostnames: z.array(z.string()).optional(),
   error: z
     .object({
       code: z.number(),
@@ -255,7 +260,7 @@ export const getDeploymentStatus = async (
   storeHash: string,
   accessToken: string,
   apiHost: string,
-) => {
+): Promise<string | undefined> => {
   consola.info('Fetching deployment status...');
 
   const spinner = yoctoSpinner().start('Fetching...');
@@ -336,7 +341,11 @@ export const getDeploymentStatus = async (
     const url = deploymentUrl.startsWith('https://') ? deploymentUrl : `https://${deploymentUrl}`;
 
     consola.success(`View your deployment at: ${colorize('blue', url)}`);
+
+    return url;
   }
+
+  return undefined;
 };
 
 export const fetchProject = async (
@@ -401,6 +410,14 @@ Example:
       'BigCommerce intrastructure project UUID. Can be found via the BigCommerce API (GET /v3/infrastructure/projects).',
     ).env('CATALYST_PROJECT_UUID'),
   )
+  .addOption(
+    new Option(
+      '--update-site-url <channelId>',
+      "BigCommerce channel ID whose site URL should be updated with this deployment's URL. When omitted, no channel is updated.",
+    )
+      .env('CATALYST_UPDATE_SITE_URL')
+      .argParser((value: string) => Number(value)),
+  )
   .addOption(
     new Option(
       '--secret <value>',
@@ -479,5 +496,34 @@ Example:
       environmentVariables,
     );
 
-    await getDeploymentStatus(deploymentUuid, storeHash, accessToken, options.apiHost);
+    const deploymentUrl = await getDeploymentStatus(
+      deploymentUuid,
+      storeHash,
+      accessToken,
+      options.apiHost,
+    );
+
+    const channelId: number | undefined = options.updateSiteUrl;
+
+    if (!channelId) {
+      return;
+    }
+
+    if (!deploymentUrl) {
+      consola.warn('Skipping channel site URL update: deployment did not return a URL.');
+
+      return;
+    }
+
+    try {
+      await updateChannelSiteUrl(channelId, deploymentUrl, storeHash, accessToken, options.apiHost);
+      consola.success(`Updated channel ${channelId} site URL to ${deploymentUrl}.`);
+    } catch (error) {
+      consola.warn(
+        `Failed to update channel site URL: ${error instanceof Error ? error.message : String(error)}`,
+      );
+      consola.info(
+        'Update it manually in the control panel, or re-run after `catalyst auth login` if the token is missing the store_channel_settings scope.',
+      );
+    }
   });
diff --git a/packages/catalyst/src/cli/lib/auth.ts b/packages/catalyst/src/cli/lib/auth.ts
index b59922b438..1aa1baac21 100644
--- a/packages/catalyst/src/cli/lib/auth.ts
+++ b/packages/catalyst/src/cli/lib/auth.ts
@@ -6,6 +6,7 @@ export const DEVICE_OAUTH_SCOPES = [
   'store_infrastructure_deployments_manage',
   'store_infrastructure_logs_read_only',
   'store_infrastructure_projects_manage',
+  'store_channel_settings',
 ].join(' ');
 export const DEFAULT_LOGIN_URL = 'https://login.bigcommerce.com';
 
diff --git a/packages/catalyst/src/cli/lib/channels.spec.ts b/packages/catalyst/src/cli/lib/channels.spec.ts
new file mode 100644
index 0000000000..474b330731
--- /dev/null
+++ b/packages/catalyst/src/cli/lib/channels.spec.ts
@@ -0,0 +1,107 @@
+import { http, HttpResponse } from 'msw';
+import { afterAll, beforeAll, describe, expect, test, vi } from 'vitest';
+
+import { server } from '../../../tests/mocks/node';
+
+import { updateChannelSiteUrl } from './channels';
+
+const storeHash = 'test-store';
+const accessToken = 'test-token';
+const apiHost = 'api.bigcommerce.com';
+const channelId = 1;
+
+beforeAll(() => {
+  vi.mock('./telemetry', () => {
+    const instance = {
+      identify: vi.fn(),
+      isEnabled: vi.fn(() => true),
+      track: vi.fn(),
+      correlationId: 'test-session-uuid',
+      commandName: 'unknown',
+      durationMs: vi.fn().mockReturnValue(0),
+      analytics: {
+        closeAndFlush: vi.fn().mockResolvedValue(undefined),
+      },
+    };
+
+    return {
+      Telemetry: vi.fn().mockImplementation(() => instance),
+      getTelemetry: vi.fn(() => instance),
+      resetTelemetry: vi.fn(),
+    };
+  });
+});
+
+afterAll(() => {
+  vi.restoreAllMocks();
+});
+
+describe('updateChannelSiteUrl', () => {
+  test('PUTs the URL and returns parsed channel site', async () => {
+    let receivedBody: unknown;
+
+    server.use(
+      http.put(
+        'https://:apiHost/stores/:storeHash/v3/channels/:channelId/site',
+        async ({ request }) => {
+          receivedBody = await request.json();
+
+          return HttpResponse.json({
+            data: {
+              id: 42,
+              url: 'https://new.example.com',
+              channel_id: channelId,
+            },
+          });
+        },
+      ),
+    );
+
+    const result = await updateChannelSiteUrl(
+      channelId,
+      'https://new.example.com',
+      storeHash,
+      accessToken,
+      apiHost,
+    );
+
+    expect(receivedBody).toEqual({ url: 'https://new.example.com' });
+    expect(result).toEqual({ id: 42, url: 'https://new.example.com', channelId });
+  });
+
+  test('throws with re-auth hint on 401', async () => {
+    server.use(
+      http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () =>
+        HttpResponse.json({}, { status: 401 }),
+      ),
+    );
+
+    await expect(
+      updateChannelSiteUrl(channelId, 'https://x.example', storeHash, accessToken, apiHost),
+    ).rejects.toThrow('Re-run `catalyst auth login`');
+  });
+
+  test('throws with re-auth hint on 403', async () => {
+    server.use(
+      http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () =>
+        HttpResponse.json({}, { status: 403 }),
+      ),
+    );
+
+    await expect(
+      updateChannelSiteUrl(channelId, 'https://x.example', storeHash, accessToken, apiHost),
+    ).rejects.toThrow('Re-run `catalyst auth login`');
+  });
+
+  test('throws with status on other errors', async () => {
+    server.use(
+      http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () =>
+        HttpResponse.json({}, { status: 500 }),
+      ),
+    );
+
+    await expect(
+      updateChannelSiteUrl(channelId, 'https://x.example', storeHash, accessToken, apiHost),
+    ).rejects.toThrow('Failed to update channel site: 500');
+  });
+});
diff --git a/packages/catalyst/src/cli/lib/channels.ts b/packages/catalyst/src/cli/lib/channels.ts
new file mode 100644
index 0000000000..cf5872bbd1
--- /dev/null
+++ b/packages/catalyst/src/cli/lib/channels.ts
@@ -0,0 +1,54 @@
+import { z } from 'zod';
+
+import { getTelemetry } from './telemetry';
+
+const channelSiteSchema = z.object({
+  data: z.object({
+    id: z.number(),
+    url: z.string(),
+    channel_id: z.number(),
+  }),
+});
+
+export interface ChannelSite {
+  id: number;
+  url: string;
+  channelId: number;
+}
+
+export async function updateChannelSiteUrl(
+  channelId: number,
+  siteUrl: string,
+  storeHash: string,
+  accessToken: string,
+  apiHost: string,
+): Promise<ChannelSite> {
+  const response = await fetch(
+    `https://${apiHost}/stores/${storeHash}/v3/channels/${channelId}/site`,
+    {
+      method: 'PUT',
+      headers: {
+        'X-Auth-Token': accessToken,
+        'Content-Type': 'application/json',
+        Accept: 'application/json',
+        'X-Correlation-Id': getTelemetry().correlationId,
+      },
+      body: JSON.stringify({ url: siteUrl }),
+    },
+  );
+
+  if (response.status === 401 || response.status === 403) {
+    throw new Error(
+      `Failed to update channel site (${response.status}). Re-run \`catalyst auth login\` to refresh your access token with the store_channel_settings scope.`,
+    );
+  }
+
+  if (!response.ok) {
+    throw new Error(`Failed to update channel site: ${response.status} ${response.statusText}`);
+  }
+
+  const res: unknown = await response.json();
+  const { data } = channelSiteSchema.parse(res);
+
+  return { id: data.id, url: data.url, channelId: data.channel_id };
+}
diff --git a/packages/catalyst/tests/mocks/handlers.ts b/packages/catalyst/tests/mocks/handlers.ts
index c16ea054db..65fd8d81c3 100644
--- a/packages/catalyst/tests/mocks/handlers.ts
+++ b/packages/catalyst/tests/mocks/handlers.ts
@@ -138,4 +138,12 @@ export const handlers = [
       },
     }),
   ),
+
+  // Default handler for updateChannelSiteUrl — succeeds with a generic
+  // payload. Tests that need to assert error handling should override.
+  http.put('https://:apiHost/stores/:storeHash/v3/channels/:channelId/site', () =>
+    HttpResponse.json({
+      data: { id: 1, url: 'https://example.com', channel_id: 1 },
+    }),
+  ),
 ];