diff --git a/CHANGELOG.md b/CHANGELOG.md
index 70a833a46b4b..6e38f312fa1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -55,6 +55,7 @@
 
 ### Chore & Maintenance
 
+- `[jest-watcher]` Standardize filenames ([#7314](https://github.com/facebook/jest/pull/7314))
 - `[docs]` Add synchronous test.each setup ([#7150](https://github.com/facebook/jest/pull/7150))
 - `[docs]` Add `this.extend` to the Custom Matchers API reference ([#7130](https://github.com/facebook/jest/pull/7130))
 - `[docs]` Fix default value for `coverageReporters` value in configuration docs ([#7126](https://github.com/facebook/jest/pull/7126))
diff --git a/packages/jest-circus/src/format_node_assert_errors.js b/packages/jest-circus/src/format_node_assert_errors.js
index 9bf6462823a0..9151fa9fe3fa 100644
--- a/packages/jest-circus/src/format_node_assert_errors.js
+++ b/packages/jest-circus/src/format_node_assert_errors.js
@@ -7,7 +7,7 @@
  * @flow strict-local
  */
 
-import type {DiffOptions} from 'jest-diff/src/diff_strings';
+import type {DiffOptions} from 'jest-diff/src/diffStrings';
 import type {Event, State} from 'types/Circus';
 
 import {printExpected, printReceived} from 'jest-matcher-utils';
diff --git a/packages/jest-diff/src/diff_strings.js b/packages/jest-diff/src/diffStrings.js
similarity index 100%
rename from packages/jest-diff/src/diff_strings.js
rename to packages/jest-diff/src/diffStrings.js
diff --git a/packages/jest-diff/src/index.js b/packages/jest-diff/src/index.js
index ecee23658b66..340650b779c9 100644
--- a/packages/jest-diff/src/index.js
+++ b/packages/jest-diff/src/index.js
@@ -7,12 +7,12 @@
  * @flow
  */
 
-import type {DiffOptions} from './diff_strings';
+import type {DiffOptions} from './diffStrings';
 
 import prettyFormat from 'pretty-format';
 import chalk from 'chalk';
 import getType from 'jest-get-type';
-import diffStrings from './diff_strings';
+import diffStrings from './diffStrings';
 import {NO_DIFF_MESSAGE, SIMILAR_MESSAGE} from './constants';
 
 const {
diff --git a/packages/jest-jasmine2/src/assert_support.js b/packages/jest-jasmine2/src/assert_support.js
index 74414a0051f8..dd991bb7603c 100644
--- a/packages/jest-jasmine2/src/assert_support.js
+++ b/packages/jest-jasmine2/src/assert_support.js
@@ -7,7 +7,7 @@
  * @flow
  */
 
-import type {DiffOptions} from 'jest-diff/src/diff_strings';
+import type {DiffOptions} from 'jest-diff/src/diffStrings';
 
 import {printReceived, printExpected} from 'jest-matcher-utils';
 import chalk from 'chalk';
diff --git a/packages/jest-watcher/src/base_watch_plugin.js b/packages/jest-watcher/src/BaseWatchPlugin.js
similarity index 100%
rename from packages/jest-watcher/src/base_watch_plugin.js
rename to packages/jest-watcher/src/BaseWatchPlugin.js
diff --git a/packages/jest-watcher/src/jest_hooks.js b/packages/jest-watcher/src/JestHooks.js
similarity index 100%
rename from packages/jest-watcher/src/jest_hooks.js
rename to packages/jest-watcher/src/JestHooks.js
diff --git a/packages/jest-watcher/src/pattern_prompt.js b/packages/jest-watcher/src/PatternPrompt.js
similarity index 100%
rename from packages/jest-watcher/src/pattern_prompt.js
rename to packages/jest-watcher/src/PatternPrompt.js
diff --git a/packages/jest-watcher/src/index.js b/packages/jest-watcher/src/index.js
index fbe13be62b2c..ec145efba3bd 100644
--- a/packages/jest-watcher/src/index.js
+++ b/packages/jest-watcher/src/index.js
@@ -7,9 +7,9 @@
  * @flow
  */
 
-export {default as BaseWatchPlugin} from './base_watch_plugin';
-export {default as JestHook} from './jest_hooks';
-export {default as PatternPrompt} from './pattern_prompt';
+export {default as BaseWatchPlugin} from './BaseWatchPlugin';
+export {default as JestHook} from './JestHooks';
+export {default as PatternPrompt} from './PatternPrompt';
 export * from './constants';
 export {default as Prompt} from './lib/Prompt';
-export * from './lib/pattern_mode_helpers';
+export * from './lib/patternModeHelpers';
diff --git a/packages/jest-watcher/src/lib/__tests__/format_test_name_by_pattern.test.js b/packages/jest-watcher/src/lib/__tests__/format_test_name_by_pattern.test.js
index 08b688f77aae..16bea7d02681 100644
--- a/packages/jest-watcher/src/lib/__tests__/format_test_name_by_pattern.test.js
+++ b/packages/jest-watcher/src/lib/__tests__/format_test_name_by_pattern.test.js
@@ -9,7 +9,7 @@
 
 'use strict';
 
-import formatTestNameByPattern from '../format_test_name_by_pattern';
+import formatTestNameByPattern from '../formatTestNameByPattern';
 
 describe('for multiline test name returns', () => {
   const testNames = [
diff --git a/packages/jest-watcher/src/lib/__tests__/scroll_list.test.js b/packages/jest-watcher/src/lib/__tests__/scroll_list.test.js
index a29c327c52e1..39680db8094c 100644
--- a/packages/jest-watcher/src/lib/__tests__/scroll_list.test.js
+++ b/packages/jest-watcher/src/lib/__tests__/scroll_list.test.js
@@ -1,4 +1,4 @@
-import scroll from '../scroll_list';
+import scroll from '../scrollList';
 
 it('When offset is -1', () => {
   expect(scroll(25, {max: 10, offset: -1})).toEqual({
diff --git a/packages/jest-watcher/src/lib/format_test_name_by_pattern.js b/packages/jest-watcher/src/lib/formatTestNameByPattern.js
similarity index 100%
rename from packages/jest-watcher/src/lib/format_test_name_by_pattern.js
rename to packages/jest-watcher/src/lib/formatTestNameByPattern.js
diff --git a/packages/jest-watcher/src/lib/pattern_mode_helpers.js b/packages/jest-watcher/src/lib/patternModeHelpers.js
similarity index 100%
rename from packages/jest-watcher/src/lib/pattern_mode_helpers.js
rename to packages/jest-watcher/src/lib/patternModeHelpers.js
diff --git a/packages/jest-watcher/src/lib/scroll_list.js b/packages/jest-watcher/src/lib/scrollList.js
similarity index 88%
rename from packages/jest-watcher/src/lib/scroll_list.js
rename to packages/jest-watcher/src/lib/scrollList.js
index 913456206139..eb9d0030297d 100644
--- a/packages/jest-watcher/src/lib/scroll_list.js
+++ b/packages/jest-watcher/src/lib/scrollList.js
@@ -11,7 +11,7 @@
 
 import type {ScrollOptions} from 'types/Watch';
 
-export default function scroll(size: number, {offset, max}: ScrollOptions) {
+export default function scrollList(size: number, {offset, max}: ScrollOptions) {
   let start = 0;
   let index = Math.min(offset, size);