diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index 16f831fb611f..eae01938f0d3 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -55,7 +55,7 @@ jobs:
         run: yarn build
       - name: test typings
         run: yarn test-types
-      - name: verify TypeScript@4.2 compatibility
+      - name: verify TypeScript@4.3 compatibility
         run: yarn verify-old-ts
 
   lint:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 79a416b988a1..55e39de6c6ea 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -81,7 +81,7 @@
 ### Chore & Maintenance
 
 - `[*]` [**BREAKING**] Drop support for Node v10 and v15 and target first LTS `16.13.0` ([#12220](https://github.com/facebook/jest/pull/12220))
-- `[*]` [**BREAKING**] Drop support for `typescript@3.8`, minimum version is now `4.2` ([#11142](https://github.com/facebook/jest/pull/11142))
+- `[*]` [**BREAKING**] Drop support for `typescript@3.8`, minimum version is now `4.3` ([#11142](https://github.com/facebook/jest/pull/11142), [#12648](https://github.com/facebook/jest/pull/12648))
 - `[*]` Bundle all `.d.ts` files into a single `index.d.ts` per module ([#12345](https://github.com/facebook/jest/pull/12345))
 - `[*]` Use `globalThis` instead of `global` ([#12447](https://github.com/facebook/jest/pull/12447))
 - `[babel-jest]` [**BREAKING**] Only export `createTransformer` ([#12407](https://github.com/facebook/jest/pull/12407))
diff --git a/packages/expect/src/asymmetricMatchers.ts b/packages/expect/src/asymmetricMatchers.ts
index 9af6ce60c2a7..58390fc11421 100644
--- a/packages/expect/src/asymmetricMatchers.ts
+++ b/packages/expect/src/asymmetricMatchers.ts
@@ -131,7 +131,7 @@ class Any extends AsymmetricMatcher<any> {
     return 'Any';
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     if (this.sample == String) {
       return 'string';
     }
@@ -155,7 +155,7 @@ class Any extends AsymmetricMatcher<any> {
     return fnNameFor(this.sample);
   }
 
-  toAsymmetricMatcher() {
+  override toAsymmetricMatcher() {
     return `Any<${fnNameFor(this.sample)}>`;
   }
 }
@@ -171,7 +171,7 @@ class Anything extends AsymmetricMatcher<void> {
 
   // No getExpectedType method, because it matches either null or undefined.
 
-  toAsymmetricMatcher() {
+  override toAsymmetricMatcher() {
     return 'Anything';
   }
 }
@@ -203,7 +203,7 @@ class ArrayContaining extends AsymmetricMatcher<Array<unknown>> {
     return `Array${this.inverse ? 'Not' : ''}Containing`;
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     return 'array';
   }
 }
@@ -240,7 +240,7 @@ class ObjectContaining extends AsymmetricMatcher<Record<string, unknown>> {
     return `Object${this.inverse ? 'Not' : ''}Containing`;
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     return 'object';
   }
 }
@@ -263,7 +263,7 @@ class StringContaining extends AsymmetricMatcher<string> {
     return `String${this.inverse ? 'Not' : ''}Containing`;
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     return 'string';
   }
 }
@@ -286,7 +286,7 @@ class StringMatching extends AsymmetricMatcher<RegExp> {
     return `String${this.inverse ? 'Not' : ''}Matching`;
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     return 'string';
   }
 }
@@ -326,7 +326,7 @@ class CloseTo extends AsymmetricMatcher<number> {
     return `Number${this.inverse ? 'Not' : ''}CloseTo`;
   }
 
-  getExpectedType() {
+  override getExpectedType() {
     return 'number';
   }
 }
diff --git a/packages/expect/src/jestMatchersObject.ts b/packages/expect/src/jestMatchersObject.ts
index 121a3116f26d..090434d66f60 100644
--- a/packages/expect/src/jestMatchersObject.ts
+++ b/packages/expect/src/jestMatchersObject.ts
@@ -94,11 +94,11 @@ export const setMatchers = (
           return `${this.inverse ? 'not.' : ''}${key}`;
         }
 
-        getExpectedType() {
+        override getExpectedType() {
           return 'any';
         }
 
-        toAsymmetricMatcher() {
+        override toAsymmetricMatcher() {
           return `${this.toString()}<${this.sample.map(String).join(', ')}>`;
         }
       }
diff --git a/packages/jest-console/src/BufferedConsole.ts b/packages/jest-console/src/BufferedConsole.ts
index f65874209f8c..f30f5829a623 100644
--- a/packages/jest-console/src/BufferedConsole.ts
+++ b/packages/jest-console/src/BufferedConsole.ts
@@ -24,7 +24,7 @@ export default class BufferedConsole extends Console {
   private _timers: LogTimers = {};
   private _groupDepth = 0;
 
-  Console: typeof Console = Console;
+  override Console: typeof Console = Console;
 
   constructor() {
     super({
@@ -71,7 +71,7 @@ export default class BufferedConsole extends Console {
     );
   }
 
-  assert(value: unknown, message?: string | Error): void {
+  override assert(value: unknown, message?: string | Error): void {
     try {
       assert(value, message);
     } catch (error: any) {
@@ -79,7 +79,7 @@ export default class BufferedConsole extends Console {
     }
   }
 
-  count(label: string = 'default'): void {
+  override count(label: string = 'default'): void {
     if (!this._counters[label]) {
       this._counters[label] = 0;
     }
@@ -87,28 +87,28 @@ export default class BufferedConsole extends Console {
     this._log('count', format(`${label}: ${++this._counters[label]}`));
   }
 
-  countReset(label: string = 'default'): void {
+  override countReset(label: string = 'default'): void {
     this._counters[label] = 0;
   }
 
-  debug(firstArg: unknown, ...rest: Array<unknown>): void {
+  override debug(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('debug', format(firstArg, ...rest));
   }
 
-  dir(firstArg: unknown, options: InspectOptions = {}): void {
+  override dir(firstArg: unknown, options: InspectOptions = {}): void {
     const representation = inspect(firstArg, options);
     this._log('dir', formatWithOptions(options, representation));
   }
 
-  dirxml(firstArg: unknown, ...rest: Array<unknown>): void {
+  override dirxml(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('dirxml', format(firstArg, ...rest));
   }
 
-  error(firstArg: unknown, ...rest: Array<unknown>): void {
+  override error(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('error', format(firstArg, ...rest));
   }
 
-  group(title?: string, ...rest: Array<unknown>): void {
+  override group(title?: string, ...rest: Array<unknown>): void {
     this._groupDepth++;
 
     if (title || rest.length > 0) {
@@ -116,7 +116,7 @@ export default class BufferedConsole extends Console {
     }
   }
 
-  groupCollapsed(title?: string, ...rest: Array<unknown>): void {
+  override groupCollapsed(title?: string, ...rest: Array<unknown>): void {
     this._groupDepth++;
 
     if (title || rest.length > 0) {
@@ -124,21 +124,21 @@ export default class BufferedConsole extends Console {
     }
   }
 
-  groupEnd(): void {
+  override groupEnd(): void {
     if (this._groupDepth > 0) {
       this._groupDepth--;
     }
   }
 
-  info(firstArg: unknown, ...rest: Array<unknown>): void {
+  override info(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('info', format(firstArg, ...rest));
   }
 
-  log(firstArg: unknown, ...rest: Array<unknown>): void {
+  override log(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('log', format(firstArg, ...rest));
   }
 
-  time(label: string = 'default'): void {
+  override time(label: string = 'default'): void {
     if (this._timers[label]) {
       return;
     }
@@ -146,7 +146,7 @@ export default class BufferedConsole extends Console {
     this._timers[label] = new Date();
   }
 
-  timeEnd(label: string = 'default'): void {
+  override timeEnd(label: string = 'default'): void {
     const startTime = this._timers[label];
 
     if (startTime) {
@@ -157,7 +157,7 @@ export default class BufferedConsole extends Console {
     }
   }
 
-  timeLog(label = 'default', ...data: Array<unknown>): void {
+  override timeLog(label = 'default', ...data: Array<unknown>): void {
     const startTime = this._timers[label];
 
     if (startTime) {
@@ -167,7 +167,7 @@ export default class BufferedConsole extends Console {
     }
   }
 
-  warn(firstArg: unknown, ...rest: Array<unknown>): void {
+  override warn(firstArg: unknown, ...rest: Array<unknown>): void {
     this._log('warn', format(firstArg, ...rest));
   }
 
diff --git a/packages/jest-console/src/CustomConsole.ts b/packages/jest-console/src/CustomConsole.ts
index a02850252d31..a363ad939c3b 100644
--- a/packages/jest-console/src/CustomConsole.ts
+++ b/packages/jest-console/src/CustomConsole.ts
@@ -22,7 +22,7 @@ export default class CustomConsole extends Console {
   private _timers: LogTimers = {};
   private _groupDepth = 0;
 
-  Console: typeof Console = Console;
+  override Console: typeof Console = Console;
 
   constructor(
     stdout: NodeJS.WriteStream,
@@ -49,7 +49,7 @@ export default class CustomConsole extends Console {
     );
   }
 
-  assert(value: unknown, message?: string | Error): asserts value {
+  override assert(value: unknown, message?: string | Error): asserts value {
     try {
       assert(value, message);
     } catch (error: any) {
@@ -57,7 +57,7 @@ export default class CustomConsole extends Console {
     }
   }
 
-  count(label: string = 'default'): void {
+  override count(label: string = 'default'): void {
     if (!this._counters[label]) {
       this._counters[label] = 0;
     }
@@ -65,28 +65,28 @@ export default class CustomConsole extends Console {
     this._log('count', format(`${label}: ${++this._counters[label]}`));
   }
 
-  countReset(label: string = 'default'): void {
+  override countReset(label: string = 'default'): void {
     this._counters[label] = 0;
   }
 
-  debug(firstArg: unknown, ...args: Array<unknown>): void {
+  override debug(firstArg: unknown, ...args: Array<unknown>): void {
     this._log('debug', format(firstArg, ...args));
   }
 
-  dir(firstArg: unknown, options: InspectOptions = {}): void {
+  override dir(firstArg: unknown, options: InspectOptions = {}): void {
     const representation = inspect(firstArg, options);
     this._log('dir', formatWithOptions(options, representation));
   }
 
-  dirxml(firstArg: unknown, ...args: Array<unknown>): void {
+  override dirxml(firstArg: unknown, ...args: Array<unknown>): void {
     this._log('dirxml', format(firstArg, ...args));
   }
 
-  error(firstArg: unknown, ...args: Array<unknown>): void {
+  override error(firstArg: unknown, ...args: Array<unknown>): void {
     this._logError('error', format(firstArg, ...args));
   }
 
-  group(title?: string, ...args: Array<unknown>): void {
+  override group(title?: string, ...args: Array<unknown>): void {
     this._groupDepth++;
 
     if (title || args.length > 0) {
@@ -94,7 +94,7 @@ export default class CustomConsole extends Console {
     }
   }
 
-  groupCollapsed(title?: string, ...args: Array<unknown>): void {
+  override groupCollapsed(title?: string, ...args: Array<unknown>): void {
     this._groupDepth++;
 
     if (title || args.length > 0) {
@@ -102,21 +102,21 @@ export default class CustomConsole extends Console {
     }
   }
 
-  groupEnd(): void {
+  override groupEnd(): void {
     if (this._groupDepth > 0) {
       this._groupDepth--;
     }
   }
 
-  info(firstArg: unknown, ...args: Array<unknown>): void {
+  override info(firstArg: unknown, ...args: Array<unknown>): void {
     this._log('info', format(firstArg, ...args));
   }
 
-  log(firstArg: unknown, ...args: Array<unknown>): void {
+  override log(firstArg: unknown, ...args: Array<unknown>): void {
     this._log('log', format(firstArg, ...args));
   }
 
-  time(label: string = 'default'): void {
+  override time(label: string = 'default'): void {
     if (this._timers[label]) {
       return;
     }
@@ -124,7 +124,7 @@ export default class CustomConsole extends Console {
     this._timers[label] = new Date();
   }
 
-  timeEnd(label: string = 'default'): void {
+  override timeEnd(label: string = 'default'): void {
     const startTime = this._timers[label];
 
     if (startTime) {
@@ -135,7 +135,7 @@ export default class CustomConsole extends Console {
     }
   }
 
-  timeLog(label = 'default', ...data: Array<unknown>): void {
+  override timeLog(label = 'default', ...data: Array<unknown>): void {
     const startTime = this._timers[label];
 
     if (startTime) {
@@ -145,7 +145,7 @@ export default class CustomConsole extends Console {
     }
   }
 
-  warn(firstArg: unknown, ...args: Array<unknown>): void {
+  override warn(firstArg: unknown, ...args: Array<unknown>): void {
     this._logError('warn', format(firstArg, ...args));
   }
 
diff --git a/packages/jest-console/src/NullConsole.ts b/packages/jest-console/src/NullConsole.ts
index 002e3a9738ff..de8d3e2ba5e2 100644
--- a/packages/jest-console/src/NullConsole.ts
+++ b/packages/jest-console/src/NullConsole.ts
@@ -8,18 +8,18 @@
 import CustomConsole from './CustomConsole';
 
 export default class NullConsole extends CustomConsole {
-  assert(): void {}
-  debug(): void {}
-  dir(): void {}
-  error(): void {}
-  info(): void {}
-  log(): void {}
-  time(): void {}
-  timeEnd(): void {}
-  timeLog(): void {}
-  trace(): void {}
-  warn(): void {}
-  group(): void {}
-  groupCollapsed(): void {}
-  groupEnd(): void {}
+  override assert(): void {}
+  override debug(): void {}
+  override dir(): void {}
+  override error(): void {}
+  override info(): void {}
+  override log(): void {}
+  override time(): void {}
+  override timeEnd(): void {}
+  override timeLog(): void {}
+  override trace(): void {}
+  override warn(): void {}
+  override group(): void {}
+  override groupCollapsed(): void {}
+  override groupEnd(): void {}
 }
diff --git a/packages/jest-core/src/TestNamePatternPrompt.ts b/packages/jest-core/src/TestNamePatternPrompt.ts
index 426a8bc45956..0449eaa8a653 100644
--- a/packages/jest-core/src/TestNamePatternPrompt.ts
+++ b/packages/jest-core/src/TestNamePatternPrompt.ts
@@ -18,7 +18,7 @@ export default class TestNamePatternPrompt extends PatternPrompt {
     super(pipe, prompt, 'tests');
   }
 
-  protected _onChange(pattern: string, options: ScrollOptions): void {
+  protected override _onChange(pattern: string, options: ScrollOptions): void {
     super._onChange(pattern, options);
     this._printPrompt(pattern);
   }
diff --git a/packages/jest-core/src/TestPathPatternPrompt.ts b/packages/jest-core/src/TestPathPatternPrompt.ts
index 6c9d948da346..86875cc1b3d4 100644
--- a/packages/jest-core/src/TestPathPatternPrompt.ts
+++ b/packages/jest-core/src/TestPathPatternPrompt.ts
@@ -18,7 +18,7 @@ export default class TestPathPatternPrompt extends PatternPrompt {
     super(pipe, prompt, 'filenames');
   }
 
-  protected _onChange(pattern: string, options: ScrollOptions): void {
+  protected override _onChange(pattern: string, options: ScrollOptions): void {
     super._onChange(pattern, options);
     this._printPrompt(pattern);
   }
diff --git a/packages/jest-core/src/plugins/FailedTestsInteractive.ts b/packages/jest-core/src/plugins/FailedTestsInteractive.ts
index 8fcb9b3f9c88..fa0853be55ff 100644
--- a/packages/jest-core/src/plugins/FailedTestsInteractive.ts
+++ b/packages/jest-core/src/plugins/FailedTestsInteractive.ts
@@ -19,7 +19,7 @@ export default class FailedTestsInteractivePlugin extends BaseWatchPlugin {
   private _failedTestAssertions?: Array<AssertionLocation>;
   private readonly _manager = new FailedTestsInteractiveMode(this._stdout);
 
-  apply(hooks: JestHookSubscriber): void {
+  override apply(hooks: JestHookSubscriber): void {
     hooks.onTestRunComplete(results => {
       this._failedTestAssertions = this.getFailedTestAssertions(results);
 
@@ -27,7 +27,7 @@ export default class FailedTestsInteractivePlugin extends BaseWatchPlugin {
     });
   }
 
-  getUsageInfo(): UsageData | null {
+  override getUsageInfo(): UsageData | null {
     if (this._failedTestAssertions?.length) {
       return {key: 'i', prompt: 'run failing tests interactively'};
     }
@@ -35,13 +35,13 @@ export default class FailedTestsInteractivePlugin extends BaseWatchPlugin {
     return null;
   }
 
-  onKey(key: string): void {
+  override onKey(key: string): void {
     if (this._manager.isActive()) {
       this._manager.put(key);
     }
   }
 
-  run(
+  override run(
     _: Config.GlobalConfig,
     updateConfigAndRun: UpdateConfigCallback,
   ): Promise<void> {
diff --git a/packages/jest-core/src/plugins/Quit.ts b/packages/jest-core/src/plugins/Quit.ts
index ac4c0646351e..c35e654565d5 100644
--- a/packages/jest-core/src/plugins/Quit.ts
+++ b/packages/jest-core/src/plugins/Quit.ts
@@ -15,7 +15,7 @@ class QuitPlugin extends BaseWatchPlugin {
     this.isInternal = true;
   }
 
-  async run(): Promise<void> {
+  override async run(): Promise<void> {
     if (typeof this._stdin.setRawMode === 'function') {
       this._stdin.setRawMode(false);
     }
@@ -23,7 +23,7 @@ class QuitPlugin extends BaseWatchPlugin {
     process.exit(0);
   }
 
-  getUsageInfo(): UsageData {
+  override getUsageInfo(): UsageData {
     return {
       key: 'q',
       prompt: 'quit watch mode',
diff --git a/packages/jest-core/src/plugins/TestNamePattern.ts b/packages/jest-core/src/plugins/TestNamePattern.ts
index 34e61f3c30c3..ea3ff104ac88 100644
--- a/packages/jest-core/src/plugins/TestNamePattern.ts
+++ b/packages/jest-core/src/plugins/TestNamePattern.ts
@@ -25,18 +25,18 @@ class TestNamePatternPlugin extends BaseWatchPlugin {
     this.isInternal = true;
   }
 
-  getUsageInfo(): UsageData {
+  override getUsageInfo(): UsageData {
     return {
       key: 't',
       prompt: 'filter by a test name regex pattern',
     };
   }
 
-  onKey(key: string): void {
+  override onKey(key: string): void {
     this._prompt.put(key);
   }
 
-  run(
+  override run(
     globalConfig: Config.GlobalConfig,
     updateConfigAndRun: UpdateConfigCallback,
   ): Promise<void> {
diff --git a/packages/jest-core/src/plugins/TestPathPattern.ts b/packages/jest-core/src/plugins/TestPathPattern.ts
index b02b74b62443..d0866db9b27f 100644
--- a/packages/jest-core/src/plugins/TestPathPattern.ts
+++ b/packages/jest-core/src/plugins/TestPathPattern.ts
@@ -25,18 +25,18 @@ class TestPathPatternPlugin extends BaseWatchPlugin {
     this.isInternal = true;
   }
 
-  getUsageInfo(): UsageData {
+  override getUsageInfo(): UsageData {
     return {
       key: 'p',
       prompt: 'filter by a filename regex pattern',
     };
   }
 
-  onKey(key: string): void {
+  override onKey(key: string): void {
     this._prompt.put(key);
   }
 
-  run(
+  override run(
     globalConfig: Config.GlobalConfig,
     updateConfigAndRun: UpdateConfigCallback,
   ): Promise<void> {
diff --git a/packages/jest-core/src/plugins/UpdateSnapshots.ts b/packages/jest-core/src/plugins/UpdateSnapshots.ts
index 1a637895d500..d783a091bd99 100644
--- a/packages/jest-core/src/plugins/UpdateSnapshots.ts
+++ b/packages/jest-core/src/plugins/UpdateSnapshots.ts
@@ -23,7 +23,7 @@ class UpdateSnapshotsPlugin extends BaseWatchPlugin {
     this._hasSnapshotFailure = false;
   }
 
-  run(
+  override run(
     _globalConfig: Config.GlobalConfig,
     updateConfigAndRun: UpdateConfigCallback,
   ): Promise<boolean> {
@@ -31,13 +31,13 @@ class UpdateSnapshotsPlugin extends BaseWatchPlugin {
     return Promise.resolve(false);
   }
 
-  apply(hooks: JestHookSubscriber): void {
+  override apply(hooks: JestHookSubscriber): void {
     hooks.onTestRunComplete(results => {
       this._hasSnapshotFailure = results.snapshot.failure;
     });
   }
 
-  getUsageInfo(): UsageData | null {
+  override getUsageInfo(): UsageData | null {
     if (this._hasSnapshotFailure) {
       return {
         key: 'u',
diff --git a/packages/jest-core/src/plugins/UpdateSnapshotsInteractive.ts b/packages/jest-core/src/plugins/UpdateSnapshotsInteractive.ts
index 63f52ff5cfcd..1961a13611cc 100644
--- a/packages/jest-core/src/plugins/UpdateSnapshotsInteractive.ts
+++ b/packages/jest-core/src/plugins/UpdateSnapshotsInteractive.ts
@@ -42,7 +42,7 @@ class UpdateSnapshotInteractivePlugin extends BaseWatchPlugin {
     return failedTestPaths;
   }
 
-  apply(hooks: JestHookSubscriber): void {
+  override apply(hooks: JestHookSubscriber): void {
     hooks.onTestRunComplete(results => {
       this._failedSnapshotTestAssertions =
         this.getFailedSnapshotTestAssertions(results);
@@ -52,13 +52,13 @@ class UpdateSnapshotInteractivePlugin extends BaseWatchPlugin {
     });
   }
 
-  onKey(key: string): void {
+  override onKey(key: string): void {
     if (this._snapshotInteractiveMode.isActive()) {
       this._snapshotInteractiveMode.put(key);
     }
   }
 
-  run(
+  override run(
     _globalConfig: Config.GlobalConfig,
     updateConfigAndRun: Function,
   ): Promise<void> {
@@ -85,7 +85,7 @@ class UpdateSnapshotInteractivePlugin extends BaseWatchPlugin {
     }
   }
 
-  getUsageInfo(): UsageData | null {
+  override getUsageInfo(): UsageData | null {
     if (this._failedSnapshotTestAssertions?.length > 0) {
       return {
         key: 'i',
diff --git a/packages/jest-reporters/src/CoverageReporter.ts b/packages/jest-reporters/src/CoverageReporter.ts
index 63da91389719..2390029f90b6 100644
--- a/packages/jest-reporters/src/CoverageReporter.ts
+++ b/packages/jest-reporters/src/CoverageReporter.ts
@@ -64,7 +64,7 @@ export default class CoverageReporter extends BaseReporter {
     this._options = options || {};
   }
 
-  onTestResult(_test: Test, testResult: TestResult): void {
+  override onTestResult(_test: Test, testResult: TestResult): void {
     if (testResult.v8Coverage) {
       this._v8CoverageResults.push(testResult.v8Coverage);
       return;
@@ -75,7 +75,7 @@ export default class CoverageReporter extends BaseReporter {
     }
   }
 
-  async onRunComplete(
+  override async onRunComplete(
     contexts: Set<Context>,
     aggregatedResults: AggregatedResult,
   ): Promise<void> {
diff --git a/packages/jest-reporters/src/DefaultReporter.ts b/packages/jest-reporters/src/DefaultReporter.ts
index 19a46dac5ab0..3af42784283e 100644
--- a/packages/jest-reporters/src/DefaultReporter.ts
+++ b/packages/jest-reporters/src/DefaultReporter.ts
@@ -127,22 +127,22 @@ export default class DefaultReporter extends BaseReporter {
     }
   }
 
-  onRunStart(
+  override onRunStart(
     aggregatedResults: AggregatedResult,
     options: ReporterOnStartOptions,
   ): void {
     this._status.runStarted(aggregatedResults, options);
   }
 
-  onTestStart(test: Test): void {
+  override onTestStart(test: Test): void {
     this._status.testStarted(test.path, test.context.config);
   }
 
-  onTestCaseResult(test: Test, testCaseResult: TestCaseResult): void {
+  override onTestCaseResult(test: Test, testCaseResult: TestCaseResult): void {
     this._status.addTestCaseResult(test, testCaseResult);
   }
 
-  onRunComplete(): void {
+  override onRunComplete(): void {
     this.forceFlushBufferedOutput();
     this._status.runFinished();
     process.stdout.write = this._out;
@@ -150,7 +150,7 @@ export default class DefaultReporter extends BaseReporter {
     clearLine(process.stderr);
   }
 
-  onTestResult(
+  override onTestResult(
     test: Test,
     testResult: TestResult,
     aggregatedResults: AggregatedResult,
diff --git a/packages/jest-reporters/src/GitHubActionsReporter.ts b/packages/jest-reporters/src/GitHubActionsReporter.ts
index dd63977df91d..b9188e701b7b 100644
--- a/packages/jest-reporters/src/GitHubActionsReporter.ts
+++ b/packages/jest-reporters/src/GitHubActionsReporter.ts
@@ -23,7 +23,7 @@ function replaceEntities(s: string): string {
 }
 
 export default class GitHubActionsReporter extends BaseReporter {
-  onRunComplete(
+  override onRunComplete(
     _contexts?: Set<Context>,
     aggregatedResults?: AggregatedResult,
   ): void {
diff --git a/packages/jest-reporters/src/NotifyReporter.ts b/packages/jest-reporters/src/NotifyReporter.ts
index 4bc77ac48999..63d8a218ea2b 100644
--- a/packages/jest-reporters/src/NotifyReporter.ts
+++ b/packages/jest-reporters/src/NotifyReporter.ts
@@ -37,7 +37,10 @@ export default class NotifyReporter extends BaseReporter {
     this._context = context;
   }
 
-  onRunComplete(contexts: Set<Context>, result: AggregatedResult): void {
+  override onRunComplete(
+    contexts: Set<Context>,
+    result: AggregatedResult,
+  ): void {
     const success =
       result.numFailedTests === 0 && result.numRuntimeErrorTestSuites === 0;
 
diff --git a/packages/jest-reporters/src/SummaryReporter.ts b/packages/jest-reporters/src/SummaryReporter.ts
index c46854a4b83f..36e59aae3bb3 100644
--- a/packages/jest-reporters/src/SummaryReporter.ts
+++ b/packages/jest-reporters/src/SummaryReporter.ts
@@ -70,7 +70,7 @@ export default class SummaryReporter extends BaseReporter {
     }
   }
 
-  onRunStart(
+  override onRunStart(
     aggregatedResults: AggregatedResult,
     options: ReporterOnStartOptions,
   ): void {
@@ -78,7 +78,7 @@ export default class SummaryReporter extends BaseReporter {
     this._estimatedTime = options.estimatedTime;
   }
 
-  onRunComplete(
+  override onRunComplete(
     contexts: Set<Context>,
     aggregatedResults: AggregatedResult,
   ): void {
diff --git a/packages/jest-reporters/src/VerboseReporter.ts b/packages/jest-reporters/src/VerboseReporter.ts
index 4476e895d98d..919767dbdf9b 100644
--- a/packages/jest-reporters/src/VerboseReporter.ts
+++ b/packages/jest-reporters/src/VerboseReporter.ts
@@ -20,9 +20,9 @@ import type {Test} from './types';
 const {ICONS} = specialChars;
 
 export default class VerboseReporter extends DefaultReporter {
-  protected _globalConfig: Config.GlobalConfig;
+  protected override _globalConfig: Config.GlobalConfig;
 
-  static readonly filename = __filename;
+  static override readonly filename = __filename;
 
   constructor(globalConfig: Config.GlobalConfig) {
     super(globalConfig);
@@ -31,7 +31,7 @@ export default class VerboseReporter extends DefaultReporter {
 
   // Verbose mode is for debugging. Buffering of output is undesirable.
   // See https://github.com/facebook/jest/issues/8208
-  protected __wrapStdio(
+  protected override __wrapStdio(
     stream: NodeJS.WritableStream | NodeJS.WriteStream,
   ): void {
     const write = stream.write.bind(stream);
@@ -71,7 +71,7 @@ export default class VerboseReporter extends DefaultReporter {
     return root;
   }
 
-  onTestResult(
+  override onTestResult(
     test: Test,
     result: TestResult,
     aggregatedResults: AggregatedResult,
diff --git a/packages/jest-validate/src/utils.ts b/packages/jest-validate/src/utils.ts
index e327bce87f7e..d6890f7914cd 100644
--- a/packages/jest-validate/src/utils.ts
+++ b/packages/jest-validate/src/utils.ts
@@ -25,8 +25,8 @@ export const formatPrettyObject = (value: unknown): string =>
     : JSON.stringify(value, null, 2).split('\n').join('\n    ');
 
 export class ValidationError extends Error {
-  name: string;
-  message: string;
+  override name: string;
+  override message: string;
 
   constructor(name: string, message: string, comment?: string | null) {
     super();
diff --git a/packages/jest-worker/src/WorkerPool.ts b/packages/jest-worker/src/WorkerPool.ts
index 0bf2a72c3ed1..694858b9a863 100644
--- a/packages/jest-worker/src/WorkerPool.ts
+++ b/packages/jest-worker/src/WorkerPool.ts
@@ -27,7 +27,7 @@ class WorkerPool extends BaseWorkerPool implements WorkerPoolInterface {
     this.getWorkerById(workerId).send(request, onStart, onEnd, onCustomMessage);
   }
 
-  createWorker(workerOptions: WorkerOptions): WorkerInterface {
+  override createWorker(workerOptions: WorkerOptions): WorkerInterface {
     let Worker;
     if (this._options.enableWorkerThreads) {
       Worker = require('./workers/NodeThreadsWorker').default;
diff --git a/scripts/verifyOldTs.mjs b/scripts/verifyOldTs.mjs
index 481c500ad49e..9ad40b74fe6a 100644
--- a/scripts/verifyOldTs.mjs
+++ b/scripts/verifyOldTs.mjs
@@ -33,7 +33,7 @@ const tsConfig = {
 };
 /* eslint-enable */
 
-const tsVersion = '4.2';
+const tsVersion = '4.3';
 
 function smoketest() {
   const jestDirectory = path.resolve(
diff --git a/tsconfig.json b/tsconfig.json
index cff2131d1fb2..574e1e6ec482 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -12,6 +12,7 @@
     /* Additional Checks */
     "noUnusedLocals": true,
     "noUnusedParameters": true,
+    "noImplicitOverride": true,
     "noImplicitReturns": true,
     "noFallthroughCasesInSwitch": true,