diff --git a/packages/toolkit/src/query/fetchBaseQuery.ts b/packages/toolkit/src/query/fetchBaseQuery.ts
index e8d152dbe3..1b5eb13da2 100644
--- a/packages/toolkit/src/query/fetchBaseQuery.ts
+++ b/packages/toolkit/src/query/fetchBaseQuery.ts
@@ -27,6 +27,13 @@ export interface FetchArgs extends CustomRequestInit {
   validateStatus?: (response: Response, body: any) => boolean
 }
 
+/**
+ * A mini-wrapper that passes arguments straight through to
+ * {@link [fetch](https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API)}.
+ * Avoids storing `fetch` in a closure, in order to permit mocking/monkey-patching.
+ */
+const defaultFetchFn: typeof fetch = (...args) => fetch(...args)
+
 const defaultValidateStatus = (response: Response) =>
   response.status >= 200 && response.status <= 299
 
@@ -118,7 +125,7 @@ export type FetchBaseQueryMeta = { request: Request; response: Response }
 export function fetchBaseQuery({
   baseUrl,
   prepareHeaders = (x) => x,
-  fetchFn = fetch,
+  fetchFn = defaultFetchFn,
   ...baseFetchOptions
 }: FetchBaseQueryArgs = {}): BaseQueryFn<
   string | FetchArgs,
@@ -127,6 +134,11 @@ export function fetchBaseQuery({
   {},
   FetchBaseQueryMeta
 > {
+  if (typeof fetch === 'undefined' && fetchFn === defaultFetchFn) {
+    console.warn(
+      'Warning: `fetch` is not available. Please supply a custom `fetchFn` property to use `fetchBaseQuery` on SSR environments.'
+    )
+  }
   return async (arg, { signal, getState }) => {
     let {
       url,
diff --git a/packages/toolkit/src/query/tests/fetchBaseQuery.test.tsx b/packages/toolkit/src/query/tests/fetchBaseQuery.test.tsx
index 0a3b4e03b0..50060c6cb9 100644
--- a/packages/toolkit/src/query/tests/fetchBaseQuery.test.tsx
+++ b/packages/toolkit/src/query/tests/fetchBaseQuery.test.tsx
@@ -531,6 +531,34 @@ describe('fetchFn', () => {
 
     expect(request.url).toEqual(`${baseUrl}/echo?apple=fruit`)
   })
+
+  test('respects mocking window.fetch after a fetch base query is created', async () => {
+    const baseUrl = 'http://example.com'
+    const baseQuery = fetchBaseQuery({ baseUrl })
+
+    const fakeResponse = {
+      ok: true,
+      status: 200,
+      text: async () => `{ "url": "mock-return-url" }`,
+      clone: () => fakeResponse
+    }
+
+    const spiedFetch = jest.spyOn(window, 'fetch');
+    spiedFetch.mockResolvedValueOnce(fakeResponse as any);
+
+    const { data } = await baseQuery(
+      { url: '/echo' },
+      {
+        signal: new AbortController().signal,
+        dispatch: storeRef.store.dispatch,
+        getState: storeRef.store.getState,
+      },
+      {}
+    )
+    expect(data).toEqual({url: 'mock-return-url'})
+
+    spiedFetch.mockClear();
+  })
 })
 
 describe('FormData', () => {
diff --git a/yarn.lock b/yarn.lock
index 09161940c4..3532fde762 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3384,9 +3384,12 @@ __metadata:
   resolution: "@examples-query-react/basic@workspace:examples/query/react/basic"
   dependencies:
     "@reduxjs/toolkit": ^1.6.0-rc.1
+    "@testing-library/react": ^12.0.0
+    "@types/jest": ^26.0.23
     "@types/react": 17.0.0
     "@types/react-dom": 17.0.0
     "@types/react-redux": 7.1.9
+    msw: ^0.30.0
     react: 17.0.0
     react-dom: 17.0.0
     react-redux: 7.2.2
@@ -3965,6 +3968,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@jest/types@npm:^27.0.6":
+  version: 27.0.6
+  resolution: "@jest/types@npm:27.0.6"
+  dependencies:
+    "@types/istanbul-lib-coverage": ^2.0.0
+    "@types/istanbul-reports": ^3.0.0
+    "@types/node": "*"
+    "@types/yargs": ^16.0.0
+    chalk: ^4.0.0
+  checksum: 86c1d8707ffcf8fb3574fa6865e1768d771c83494df5bfdc81199cac81fdbe947c69a7c113d03b7bf21c926bbfefffcfe7253138d6e52bb61a1386e05aff2a6b
+  languageName: node
+  linkType: hard
+
 "@manaflair/redux-batch@npm:^1.0.0":
   version: 1.0.0
   resolution: "@manaflair/redux-batch@npm:1.0.0"
@@ -4076,7 +4092,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@mswjs/cookies@npm:^0.1.4":
+"@mswjs/cookies@npm:^0.1.4, @mswjs/cookies@npm:^0.1.5":
   version: 0.1.6
   resolution: "@mswjs/cookies@npm:0.1.6"
   dependencies:
@@ -4107,6 +4123,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@mswjs/interceptors@npm:^0.11.1":
+  version: 0.11.1
+  resolution: "@mswjs/interceptors@npm:0.11.1"
+  dependencies:
+    "@open-draft/until": ^1.0.3
+    debug: ^4.3.0
+    headers-utils: ^3.0.2
+    strict-event-emitter: ^0.2.0
+    xmldom: ^0.6.0
+  checksum: 8227109c7dacc4d1bc331ea7e45ca5a07196d2ab87c387d2225f2bee8cb3aad906afad4d62442e76852c5bd54b89ab0278ea6b4a0a6bab2eda76a338c1857815
+  languageName: node
+  linkType: hard
+
 "@mswjs/interceptors@npm:^0.8.0":
   version: 0.8.1
   resolution: "@mswjs/interceptors@npm:0.8.1"
@@ -4781,6 +4810,22 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@testing-library/dom@npm:^8.0.0":
+  version: 8.1.0
+  resolution: "@testing-library/dom@npm:8.1.0"
+  dependencies:
+    "@babel/code-frame": ^7.10.4
+    "@babel/runtime": ^7.12.5
+    "@types/aria-query": ^4.2.0
+    aria-query: ^4.2.2
+    chalk: ^4.1.0
+    dom-accessibility-api: ^0.5.6
+    lz-string: ^1.4.4
+    pretty-format: ^27.0.2
+  checksum: 5b8c04123a50f2d3e01d2b1c8c929a009e83caca5b1813785330657d387914dedd87f0d158e94c6039b08d00c19a17a61a66fd9fca39cb67115718314dcced5a
+  languageName: node
+  linkType: hard
+
 "@testing-library/react-hooks@npm:^5.1.2":
   version: 5.1.3
   resolution: "@testing-library/react-hooks@npm:5.1.3"
@@ -4817,6 +4862,19 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@testing-library/react@npm:^12.0.0":
+  version: 12.0.0
+  resolution: "@testing-library/react@npm:12.0.0"
+  dependencies:
+    "@babel/runtime": ^7.12.5
+    "@testing-library/dom": ^8.0.0
+  peerDependencies:
+    react: "*"
+    react-dom: "*"
+  checksum: 2b5da0513f5de02636c1610625ca55222ea5c89ee271a9c9c3bcc1282010b9649b8168b8c84d8dc37a29daf0a8c909280ccaf8648dd09c19f2e2d640ea7f9459
+  languageName: node
+  linkType: hard
+
 "@testing-library/user-event@npm:^13.1.5":
   version: 13.1.9
   resolution: "@testing-library/user-event@npm:13.1.9"
@@ -5072,6 +5130,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/jest@npm:^26.0.23":
+  version: 26.0.24
+  resolution: "@types/jest@npm:26.0.24"
+  dependencies:
+    jest-diff: ^26.0.0
+    pretty-format: ^26.0.0
+  checksum: e5d3651c1edf197011d19ee8f4bacd52667fa673d1b2ffbfbce624208d643fd4372ebb31fa8a1d89843a7705f142e38076e25e1e7b67f3aacafd6ae8bc77cbcf
+  languageName: node
+  linkType: hard
+
 "@types/js-levenshtein@npm:^1.1.0":
   version: 1.1.0
   resolution: "@types/js-levenshtein@npm:1.1.0"
@@ -5507,6 +5575,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/yargs@npm:^16.0.0":
+  version: 16.0.4
+  resolution: "@types/yargs@npm:16.0.4"
+  dependencies:
+    "@types/yargs-parser": "*"
+  checksum: 929334a45c548f78e5aa756282b8abe17c0c7233eaaf414795808ab36a5f9957b3bc8c84151429d919fd2ac04ed2ce99853a85aea65823b4f669643656a3c65e
+  languageName: node
+  linkType: hard
+
 "@types/yargs@npm:^16.0.1":
   version: 16.0.3
   resolution: "@types/yargs@npm:16.0.3"
@@ -6319,6 +6396,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ansi-styles@npm:^5.0.0":
+  version: 5.2.0
+  resolution: "ansi-styles@npm:5.2.0"
+  checksum: 10b01465c7a49cbfcc055188e3b79b00db6283319bb53c0d20ca9ad114d1477d6f48c1d01a3ed9678f616566ec33f11116926dfaa162fa7be9ee7d5d2c2ea7e1
+  languageName: node
+  linkType: hard
+
 "anymatch@npm:^2.0.0":
   version: 2.0.0
   resolution: "anymatch@npm:2.0.0"
@@ -12703,6 +12787,28 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
+"inquirer@npm:^8.1.0":
+  version: 8.1.1
+  resolution: "inquirer@npm:8.1.1"
+  dependencies:
+    ansi-escapes: ^4.2.1
+    chalk: ^4.1.1
+    cli-cursor: ^3.1.0
+    cli-width: ^3.0.0
+    external-editor: ^3.0.3
+    figures: ^3.0.0
+    lodash: ^4.17.21
+    mute-stream: 0.0.8
+    ora: ^5.3.0
+    run-async: ^2.4.0
+    rxjs: ^6.6.6
+    string-width: ^4.1.0
+    strip-ansi: ^6.0.0
+    through: ^2.3.6
+  checksum: e5cd5c1aa295970666009b555af2e954dc16144efb5fd5c08642653598f88f23a41dda9626c44bc5e9909d8269f5e3dcdddbe18512685d772b94743f263e0f6f
+  languageName: node
+  linkType: hard
+
 "internal-ip@npm:^4.3.0":
   version: 4.3.0
   resolution: "internal-ip@npm:4.3.0"
@@ -13536,7 +13642,7 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"jest-diff@npm:^26.6.2":
+"jest-diff@npm:^26.0.0, jest-diff@npm:^26.6.2":
   version: 26.6.2
   resolution: "jest-diff@npm:26.6.2"
   dependencies:
@@ -15512,6 +15618,35 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
+"msw@npm:^0.30.0":
+  version: 0.30.1
+  resolution: "msw@npm:0.30.1"
+  dependencies:
+    "@mswjs/cookies": ^0.1.5
+    "@mswjs/interceptors": ^0.11.1
+    "@open-draft/until": ^1.0.3
+    "@types/cookie": ^0.4.0
+    "@types/inquirer": ^7.3.1
+    "@types/js-levenshtein": ^1.1.0
+    chalk: ^4.1.1
+    chokidar: ^3.4.2
+    cookie: ^0.4.1
+    graphql: ^15.4.0
+    headers-utils: ^3.0.2
+    inquirer: ^8.1.0
+    js-levenshtein: ^1.1.6
+    node-fetch: ^2.6.1
+    node-match-path: ^0.6.3
+    statuses: ^2.0.0
+    strict-event-emitter: ^0.2.0
+    type-fest: ^1.1.3
+    yargs: ^17.0.1
+  bin:
+    msw: cli/index.js
+  checksum: 29706bdd694e98c5d536f12ebb1863d364e1643dccd9bc16e0ff4d8379f55f9e227d19b4dec18c8b070bdacc473efc9fcb370387620050760bda39085da5bf0a
+  languageName: node
+  linkType: hard
+
 "multicast-dns-service-types@npm:^1.1.0":
   version: 1.1.0
   resolution: "multicast-dns-service-types@npm:1.1.0"
@@ -15717,7 +15852,7 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"node-match-path@npm:^0.6.1":
+"node-match-path@npm:^0.6.1, node-match-path@npm:^0.6.3":
   version: 0.6.3
   resolution: "node-match-path@npm:0.6.3"
   checksum: f93cfdbc7035485c2211598b9000eabe28bf8c8d234ebb165ed7eeb7070b50f5fba0871f3fa6acca2604cce38ac3e7e333ef6a3e8e5ba82e40a0e38d3748e27d
@@ -16146,6 +16281,23 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
+"ora@npm:^5.3.0":
+  version: 5.4.1
+  resolution: "ora@npm:5.4.1"
+  dependencies:
+    bl: ^4.1.0
+    chalk: ^4.1.0
+    cli-cursor: ^3.1.0
+    cli-spinners: ^2.5.0
+    is-interactive: ^1.0.0
+    is-unicode-supported: ^0.1.0
+    log-symbols: ^4.1.0
+    strip-ansi: ^6.0.0
+    wcwidth: ^1.0.1
+  checksum: 589ac687d6dfbac970f1bf4ec94f3e1cfc9e2a4dd4727a0c60dfcdef138f59b5de5694447881fa5a2793a91f0b2619a96bdd3d5425be30d155540abbe1df95b9
+  languageName: node
+  linkType: hard
+
 "ora@npm:^5.4.0":
   version: 5.4.0
   resolution: "ora@npm:5.4.0"
@@ -18121,7 +18273,7 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"pretty-format@npm:^26.6.0, pretty-format@npm:^26.6.2":
+"pretty-format@npm:^26.0.0, pretty-format@npm:^26.6.0, pretty-format@npm:^26.6.2":
   version: 26.6.2
   resolution: "pretty-format@npm:26.6.2"
   dependencies:
@@ -18133,6 +18285,18 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
+"pretty-format@npm:^27.0.2":
+  version: 27.0.6
+  resolution: "pretty-format@npm:27.0.6"
+  dependencies:
+    "@jest/types": ^27.0.6
+    ansi-regex: ^5.0.0
+    ansi-styles: ^5.0.0
+    react-is: ^17.0.1
+  checksum: 29baf8d88a35c04ef81e310e3e239c6fe4f5b0827c9bd8f660df78e94632a9677bd113a64be78cc95c52945a4369b85828f32559cfd86c1b591aa3cc39d0798d
+  languageName: node
+  linkType: hard
+
 "pretty-time@npm:^1.1.0":
   version: 1.1.0
   resolution: "pretty-time@npm:1.1.0"
@@ -19397,9 +19561,9 @@ fsevents@^1.2.7:
   languageName: node
   linkType: hard
 
-"remark-typescript-tools@npm:^1.0.7":
-  version: 1.0.7
-  resolution: "remark-typescript-tools@npm:1.0.7"
+"remark-typescript-tools@npm:^1.0.8":
+  version: 1.0.8
+  resolution: "remark-typescript-tools@npm:1.0.8"
   dependencies:
     "@microsoft/tsdoc": ^0.12.21
     prettier: ^2.1.1
@@ -19407,7 +19571,7 @@ fsevents@^1.2.7:
     unist-util-visit: ^2.0.3
   peerDependencies:
     typescript: ">=4.0"
-  checksum: ea4ae8e383b1f38b3de63deda9c9f4baae10ac58a7f164a32e50f8ac2866a9df5cc364be4334b5d7e4ab8881498f3e8660b45797b5cde1199a67cf86a1f10088
+  checksum: 2f63dfe6c0cc3a12d0d91c011df9f0b6d828693cff35628190ecd218dcb6b5b537001a3b4f8eccf18c9bc1f0584c64a72d9a0a757055fa92849ed0f6f2dd5e96
   languageName: node
   linkType: hard
 
@@ -19937,7 +20101,7 @@ resolve@~1.19.0:
   languageName: node
   linkType: hard
 
-"rxjs@npm:^6.4.0, rxjs@npm:^6.6.0, rxjs@npm:^6.6.2, rxjs@npm:^6.6.3":
+"rxjs@npm:^6.4.0, rxjs@npm:^6.6.0, rxjs@npm:^6.6.2, rxjs@npm:^6.6.3, rxjs@npm:^6.6.6":
   version: 6.6.7
   resolution: "rxjs@npm:6.6.7"
   dependencies:
@@ -21914,6 +22078,13 @@ resolve@~1.19.0:
   languageName: node
   linkType: hard
 
+"type-fest@npm:^1.1.3":
+  version: 1.2.2
+  resolution: "type-fest@npm:1.2.2"
+  checksum: 1f5510d0afa1f17523ba7f320c6e3f222fe6c1f9d15689a69460ba7fc6ae24150958ddca7e509f9abc7ec456ed187dbf2da019fd308788d53094dc25f56eda59
+  languageName: node
+  linkType: hard
+
 "type-is@npm:~1.6.17, type-is@npm:~1.6.18":
   version: 1.6.18
   resolution: "type-is@npm:1.6.18"
@@ -23046,7 +23217,7 @@ resolve@~1.19.0:
     react: 17.0.2
     react-dom: 17.0.2
     react-lite-youtube-embed: ^2.0.3
-    remark-typescript-tools: ^1.0.7
+    remark-typescript-tools: ^1.0.8
     typescript: ~4.2.4
   languageName: unknown
   linkType: soft
@@ -23499,6 +23670,13 @@ resolve@~1.19.0:
   languageName: node
   linkType: hard
 
+"xmldom@npm:^0.6.0":
+  version: 0.6.0
+  resolution: "xmldom@npm:0.6.0"
+  checksum: cca0cddf6f95e9bfa2432a9a819f97b840e6b36fad8017833f5c7d298b4fd69ef2e3e7b5dd68f1e53ec5dd4075bfc8f68e425b06928adc0a21c9bacf0af02b0c
+  languageName: node
+  linkType: hard
+
 "xtend@npm:^4.0.0, xtend@npm:^4.0.1, xtend@npm:~4.0.1":
   version: 4.0.2
   resolution: "xtend@npm:4.0.2"
@@ -23620,6 +23798,21 @@ resolve@~1.19.0:
   languageName: node
   linkType: hard
 
+"yargs@npm:^17.0.1":
+  version: 17.0.1
+  resolution: "yargs@npm:17.0.1"
+  dependencies:
+    cliui: ^7.0.2
+    escalade: ^3.1.1
+    get-caller-file: ^2.0.5
+    require-directory: ^2.1.1
+    string-width: ^4.2.0
+    y18n: ^5.0.5
+    yargs-parser: ^20.2.2
+  checksum: a7969b48d2dea129a7d4fcc3f13e88d4f94bacbd24f720b2ce19946fa9facc42cfed89c059d953091241f4e9e9000ed9dbf86e4bb4b6ceb3a26af10ddebdd0b2
+  languageName: node
+  linkType: hard
+
 "yocto-queue@npm:^0.1.0":
   version: 0.1.0
   resolution: "yocto-queue@npm:0.1.0"