diff --git a/__tests__/validate-package-json.test.ts b/__tests__/validate-package-json.test.ts
index 31bd4e8b5e8d..ef18176ecd92 100644
--- a/__tests__/validate-package-json.test.ts
+++ b/__tests__/validate-package-json.test.ts
@@ -28,7 +28,11 @@ type PackageJsonFile = {
 async function getPackagesJsonFiles(): Promise<PackageJsonFile[]> {
   const files = await Globby('packages/*/package.json');
   return Promise.all(
-    files.map((file) => fs.readJSON(file).then((content) => ({file, content}))),
+    files.map((file) =>
+      fs
+        .readJSON(file)
+        .then((content: PackageJsonFile['content']) => ({file, content})),
+    ),
   );
 }
 
diff --git a/__tests__/validate-tsconfig.test.ts b/__tests__/validate-tsconfig.test.ts
index 7a80816b7a98..e69d170502ba 100644
--- a/__tests__/validate-tsconfig.test.ts
+++ b/__tests__/validate-tsconfig.test.ts
@@ -22,7 +22,11 @@ type TsconfigFile = {
 async function getTsconfigFiles(): Promise<TsconfigFile[]> {
   const files = await Globby('packages/*/tsconfig.*');
   return Promise.all(
-    files.map((file) => fs.readJSON(file).then((content) => ({file, content}))),
+    files.map((file) =>
+      fs
+        .readJSON(file)
+        .then((content: TsconfigFile['content']) => ({file, content})),
+    ),
   );
 }
 
diff --git a/packages/create-docusaurus/src/index.ts b/packages/create-docusaurus/src/index.ts
index cc9c9408ec30..c1f592cefcd1 100755
--- a/packages/create-docusaurus/src/index.ts
+++ b/packages/create-docusaurus/src/index.ts
@@ -65,7 +65,7 @@ async function askForPackageManagerChoice(): Promise<PackageManager> {
     .map((p) => ({title: p, value: p}));
 
   return (
-    await prompts(
+    (await prompts(
       {
         type: 'select',
         name: 'packageManager',
@@ -77,7 +77,7 @@ async function askForPackageManagerChoice(): Promise<PackageManager> {
           logger.info`Falling back to name=${defaultPackageManager}`;
         },
       },
-    )
+    )) as {packageManager: PackageManager}
   ).packageManager;
 }
 
@@ -203,7 +203,7 @@ async function getGitCommand(gitStrategy: GitStrategy): Promise<string> {
     case 'copy':
       return 'git clone --recursive --depth 1';
     case 'custom': {
-      const {command} = await prompts(
+      const {command} = (await prompts(
         {
           type: 'text',
           name: 'command',
@@ -215,7 +215,7 @@ async function getGitCommand(gitStrategy: GitStrategy): Promise<string> {
             logger.info`Falling back to code=${'git clone'}`;
           },
         },
-      );
+      )) as {command: string};
       return command ?? 'git clone';
     }
     case 'deep':
@@ -245,7 +245,7 @@ async function getSiteName(
     }
     return reqName;
   }
-  const {siteName} = await prompts(
+  const {siteName} = (await prompts(
     {
       type: 'text',
       name: 'siteName',
@@ -259,7 +259,7 @@ async function getSiteName(
         process.exit(1);
       },
     },
-  );
+  )) as {siteName: string};
   return siteName;
 }
 
@@ -324,7 +324,7 @@ async function getSource(
   const template = cliOptions.gitStrategy
     ? 'Git repository'
     : (
-        await prompts(
+        (await prompts(
           {
             type: 'select',
             name: 'template',
@@ -337,10 +337,10 @@ async function getSource(
               process.exit(1);
             },
           },
-        )
+        )) as {template: Template | 'Git repository' | 'Local template'}
       ).template;
   if (template === 'Git repository') {
-    const {gitRepoUrl} = await prompts(
+    const {gitRepoUrl} = (await prompts(
       {
         type: 'text',
         name: 'gitRepoUrl',
@@ -359,7 +359,7 @@ async function getSource(
           process.exit(1);
         },
       },
-    );
+    )) as {gitRepoUrl: string};
     let strategy = cliOptions.gitStrategy;
     if (!strategy) {
       ({strategy} = await prompts(
@@ -393,7 +393,7 @@ async function getSource(
       strategy: strategy ?? 'deep',
     };
   } else if (template === 'Local template') {
-    const {templateDir} = await prompts(
+    const {templateDir} = (await prompts(
       {
         type: 'text',
         name: 'templateDir',
@@ -418,7 +418,7 @@ async function getSource(
           process.exit(1);
         },
       },
-    );
+    )) as {templateDir: string};
     return {
       type: 'local',
       path: templateDir,
@@ -442,7 +442,7 @@ async function getSource(
 }
 
 async function updatePkg(pkgPath: string, obj: {[key: string]: unknown}) {
-  const pkg = await fs.readJSON(pkgPath);
+  const pkg = (await fs.readJSON(pkgPath)) as {[key: string]: unknown};
   const newPkg = Object.assign(pkg, obj);
 
   await fs.outputFile(pkgPath, `${JSON.stringify(newPkg, null, 2)}\n`);
diff --git a/packages/docusaurus-mdx-loader/src/loader.ts b/packages/docusaurus-mdx-loader/src/loader.ts
index 06daefccf323..88fa1ecd5bdc 100644
--- a/packages/docusaurus-mdx-loader/src/loader.ts
+++ b/packages/docusaurus-mdx-loader/src/loader.ts
@@ -92,8 +92,12 @@ async function readMetadataPath(metadataPath: string) {
  *
  * `{image: "./myImage.png"}` => `{image: require("./myImage.png")}`
  */
-function createAssetsExportCode(assets: {[key: string]: unknown}) {
-  if (Object.keys(assets).length === 0) {
+function createAssetsExportCode(assets: unknown) {
+  if (
+    typeof assets !== 'object' ||
+    !assets ||
+    Object.keys(assets).length === 0
+  ) {
     return 'undefined';
   }
 
@@ -101,7 +105,7 @@ function createAssetsExportCode(assets: {[key: string]: unknown}) {
   function createAssetValueCode(assetValue: unknown): string | undefined {
     if (Array.isArray(assetValue)) {
       const arrayItemCodes = assetValue.map(
-        (item) => createAssetValueCode(item) ?? 'undefined',
+        (item: unknown) => createAssetValueCode(item) ?? 'undefined',
       );
       return `[${arrayItemCodes.join(', ')}]`;
     }
@@ -119,7 +123,7 @@ function createAssetsExportCode(assets: {[key: string]: unknown}) {
   const assetEntries = Object.entries(assets);
 
   const codeLines = assetEntries
-    .map(([key, value]) => {
+    .map(([key, value]: [string, unknown]) => {
       const assetRequireCode = createAssetValueCode(value);
       return assetRequireCode ? `"${key}": ${assetRequireCode},` : undefined;
     })
@@ -227,7 +231,7 @@ ${JSON.stringify(frontMatter, null, 2)}`;
     : undefined;
 
   const metadata = metadataJsonString
-    ? JSON.parse(metadataJsonString)
+    ? (JSON.parse(metadataJsonString) as {[key: string]: unknown})
     : undefined;
 
   const assets =
diff --git a/packages/docusaurus-mdx-loader/src/remark/headings/__tests__/index.test.ts b/packages/docusaurus-mdx-loader/src/remark/headings/__tests__/index.test.ts
index 2f9683e6e8de..f671d6f517f8 100644
--- a/packages/docusaurus-mdx-loader/src/remark/headings/__tests__/index.test.ts
+++ b/packages/docusaurus-mdx-loader/src/remark/headings/__tests__/index.test.ts
@@ -13,13 +13,14 @@ import removePosition from 'unist-util-remove-position';
 import toString from 'mdast-util-to-string';
 import visit from 'unist-util-visit';
 import slug from '../index';
+import type {Plugin} from 'unified';
 
-function process(doc, plugins = []) {
+function process(doc: string, plugins: Plugin[] = []) {
   const processor = remark().use({plugins: [...plugins, slug]});
   return removePosition(processor.runSync(processor.parse(doc)), true);
 }
 
-function heading(label, id) {
+function heading(label: string, id: string) {
   return u(
     'heading',
     {depth: 2, data: {id, hProperties: {id}}},
diff --git a/packages/docusaurus-module-type-aliases/src/index.d.ts b/packages/docusaurus-module-type-aliases/src/index.d.ts
index a000e03f2c35..ccb4bf5706fc 100644
--- a/packages/docusaurus-module-type-aliases/src/index.d.ts
+++ b/packages/docusaurus-module-type-aliases/src/index.d.ts
@@ -35,9 +35,11 @@ declare module '@generated/registry' {
 
 declare module '@generated/routes' {
   import type {RouteConfig as RRRouteConfig} from 'react-router-config';
+  import type Loadable from 'react-loadable';
 
   type RouteConfig = RRRouteConfig & {
     path: string;
+    component: ReturnType<typeof Loadable>;
   };
   const routes: RouteConfig[];
   export default routes;
diff --git a/packages/docusaurus-plugin-content-blog/src/options.ts b/packages/docusaurus-plugin-content-blog/src/options.ts
index baf927b8c671..f6fa74e726bc 100644
--- a/packages/docusaurus-plugin-content-blog/src/options.ts
+++ b/packages/docusaurus-plugin-content-blog/src/options.ts
@@ -13,7 +13,11 @@ import {
   URISchema,
 } from '@docusaurus/utils-validation';
 import {GlobExcludeDefault} from '@docusaurus/utils';
-import type {PluginOptions, Options} from '@docusaurus/plugin-content-blog';
+import type {
+  PluginOptions,
+  Options,
+  FeedType,
+} from '@docusaurus/plugin-content-blog';
 import type {OptionValidationContext} from '@docusaurus/types';
 
 export const DEFAULT_OPTIONS: PluginOptions = {
@@ -101,7 +105,7 @@ const PluginOptionSchema = Joi.object<PluginOptions>({
         Joi.alternatives().conditional(
           Joi.string().equal('all', 'rss', 'atom', 'json'),
           {
-            then: Joi.custom((val) =>
+            then: Joi.custom((val: FeedType | 'all') =>
               val === 'all' ? ['rss', 'atom', 'json'] : [val],
             ),
           },
diff --git a/packages/docusaurus-plugin-content-docs/src/cli.ts b/packages/docusaurus-plugin-content-docs/src/cli.ts
index 11fc39b2c400..7156d4c6e49a 100644
--- a/packages/docusaurus-plugin-content-docs/src/cli.ts
+++ b/packages/docusaurus-plugin-content-docs/src/cli.ts
@@ -53,7 +53,7 @@ async function createVersionedSidebarFile({
 
 // Tests depend on non-default export for mocking.
 export async function cliDocsVersionCommand(
-  version: string,
+  version: unknown,
   {id: pluginId, path: docsPath, sidebarPath}: PluginOptions,
   {siteDir, i18n}: LoadContext,
 ): Promise<void> {
@@ -70,7 +70,7 @@ export async function cliDocsVersionCommand(
   }
 
   // Load existing versions.
-  let versions = [];
+  let versions: string[] = [];
   const versionsJSONFile = getVersionsFilePath(siteDir, pluginId);
   if (await fs.pathExists(versionsJSONFile)) {
     versions = await fs.readJSON(versionsJSONFile);
diff --git a/packages/docusaurus-plugin-content-docs/src/index.ts b/packages/docusaurus-plugin-content-docs/src/index.ts
index 422dfcbe3ea9..982895957382 100644
--- a/packages/docusaurus-plugin-content-docs/src/index.ts
+++ b/packages/docusaurus-plugin-content-docs/src/index.ts
@@ -100,7 +100,7 @@ export default async function pluginContentDocs(
         .command(command)
         .arguments('<version>')
         .description(commandDescription)
-        .action((version) => {
+        .action((version: unknown) => {
           cliDocsVersionCommand(version, options, context);
         });
     },
diff --git a/packages/docusaurus-plugin-content-docs/src/options.ts b/packages/docusaurus-plugin-content-docs/src/options.ts
index 047f59ff3940..27b9118a718f 100644
--- a/packages/docusaurus-plugin-content-docs/src/options.ts
+++ b/packages/docusaurus-plugin-content-docs/src/options.ts
@@ -98,7 +98,7 @@ const OptionsSchema = Joi.object<PluginOptions>({
       Joi.function(),
       // Convert boolean values to functions
       Joi.alternatives().conditional(Joi.boolean(), {
-        then: Joi.custom((val) =>
+        then: Joi.custom((val: boolean) =>
           val ? DefaultNumberPrefixParser : DisabledNumberPrefixParser,
         ),
       }),
diff --git a/packages/docusaurus-plugin-content-docs/src/versions/files.ts b/packages/docusaurus-plugin-content-docs/src/versions/files.ts
index 6b7464ee3049..f9ef69c82944 100644
--- a/packages/docusaurus-plugin-content-docs/src/versions/files.ts
+++ b/packages/docusaurus-plugin-content-docs/src/versions/files.ts
@@ -95,7 +95,7 @@ async function readVersionsFile(
 ): Promise<string[] | null> {
   const versionsFilePath = getVersionsFilePath(siteDir, pluginId);
   if (await fs.pathExists(versionsFilePath)) {
-    const content = await fs.readJSON(versionsFilePath);
+    const content: unknown = await fs.readJSON(versionsFilePath);
     validateVersionNames(content);
     return content;
   }
diff --git a/packages/docusaurus-plugin-debug/src/theme/DebugJsonView/index.tsx b/packages/docusaurus-plugin-debug/src/theme/DebugJsonView/index.tsx
index e6d981234dde..d22d4a015b3c 100644
--- a/packages/docusaurus-plugin-debug/src/theme/DebugJsonView/index.tsx
+++ b/packages/docusaurus-plugin-debug/src/theme/DebugJsonView/index.tsx
@@ -19,8 +19,9 @@ function BrowserOnlyReactJson(props: ReactJsonViewProps) {
   return (
     <BrowserOnly>
       {() => {
-        // eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
-        const ReactJson = require('react-json-view').default;
+        const {default: ReactJson} =
+          // eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
+          require('react-json-view') as typeof import('react-json-view');
         return <ReactJson {...props} />;
       }}
     </BrowserOnly>
diff --git a/packages/docusaurus-plugin-pwa/src/registerSw.ts b/packages/docusaurus-plugin-pwa/src/registerSw.ts
index a215a656aa58..92252cc5177c 100644
--- a/packages/docusaurus-plugin-pwa/src/registerSw.ts
+++ b/packages/docusaurus-plugin-pwa/src/registerSw.ts
@@ -320,6 +320,6 @@ if (typeof window !== 'undefined') {
     addLegacyAppInstalledEventsListeners();
 
     // Then try to register the SW using lazy/dynamic imports
-    registerSW().catch((e) => console.error('registerSW failed', e));
+    registerSW().catch((e: unknown) => console.error('registerSW failed', e));
   }
 }
diff --git a/packages/docusaurus-plugin-sitemap/src/createSitemap.ts b/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
index 366714fd3f9b..052dee692014 100644
--- a/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
+++ b/packages/docusaurus-plugin-sitemap/src/createSitemap.ts
@@ -35,7 +35,7 @@ export default async function createSitemap(
     }
     // https://github.com/staylor/react-helmet-async/pull/167
     const meta = head[route]?.meta.toComponent() as unknown as
-      | ReactElement[]
+      | ReactElement<{name?: string; content?: string}>[]
       | undefined;
     return !meta?.some(
       (tag) => tag.props.name === 'robots' && tag.props.content === 'noindex',
diff --git a/packages/docusaurus-theme-classic/src/theme/Tabs/index.tsx b/packages/docusaurus-theme-classic/src/theme/Tabs/index.tsx
index 5ee9649ac226..e81a01d3fc5b 100644
--- a/packages/docusaurus-theme-classic/src/theme/Tabs/index.tsx
+++ b/packages/docusaurus-theme-classic/src/theme/Tabs/index.tsx
@@ -25,8 +25,10 @@ import styles from './styles.module.css';
 
 // A very rough duck type, but good enough to guard against mistakes while
 // allowing customization
-function isTabItem(comp: ReactElement): comp is ReactElement<TabItemProps> {
-  return typeof comp.props.value !== 'undefined';
+function isTabItem(
+  comp: ReactElement<object>,
+): comp is ReactElement<TabItemProps> {
+  return 'value' in comp.props;
 }
 
 function TabsComponent(props: Props): JSX.Element {
diff --git a/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx b/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
index 8b88da3c8ceb..b6210a2b3660 100644
--- a/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
+++ b/packages/docusaurus-theme-common/src/components/Collapsible/index.tsx
@@ -196,9 +196,7 @@ function CollapsibleBase({
   className,
   disableSSRStyle,
 }: CollapsibleBaseProps) {
-  // any because TS is a pain for HTML element refs, see https://twitter.com/sebastienlorber/status/1412784677795110914
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  const collapsibleRef = useRef<any>(null);
+  const collapsibleRef = useRef<HTMLElement>(null);
 
   useCollapseAnimation({collapsibleRef, collapsed, animation});
 
@@ -206,7 +204,7 @@ function CollapsibleBase({
     <As
       // @ts-expect-error: the "too complicated type" is produced from
       // "CollapsibleElementType" being a huge union
-      ref={collapsibleRef}
+      ref={collapsibleRef as RefObject<never>} // Refs are contravariant, which is not expressible in TS
       style={disableSSRStyle ? undefined : getSSRStyle(collapsed)}
       onTransitionEnd={(e: React.TransitionEvent) => {
         if (e.propertyName !== 'height') {
diff --git a/packages/docusaurus-theme-common/src/utils/docsUtils.tsx b/packages/docusaurus-theme-common/src/utils/docsUtils.tsx
index fd9cfb7ab141..45d92d093770 100644
--- a/packages/docusaurus-theme-common/src/utils/docsUtils.tsx
+++ b/packages/docusaurus-theme-common/src/utils/docsUtils.tsx
@@ -318,7 +318,7 @@ export function useDocRouteMetadata({
   }
 
   // For now, the sidebarName is added as route config: not ideal!
-  const sidebarName = currentDocRoute.sidebar;
+  const sidebarName = currentDocRoute.sidebar as string;
 
   const sidebarItems = sidebarName
     ? versionMetadata.docsSidebars[sidebarName]
diff --git a/packages/docusaurus-theme-translations/src/utils.ts b/packages/docusaurus-theme-translations/src/utils.ts
index da931ef454f8..95cf7f4ec712 100644
--- a/packages/docusaurus-theme-translations/src/utils.ts
+++ b/packages/docusaurus-theme-translations/src/utils.ts
@@ -23,7 +23,7 @@ import type {TranslationFileContent} from '@docusaurus/types';
 async function getPackageCodePath(packageName: string) {
   const packagePath = path.join(__dirname, '../..', packageName);
   const packageJsonPath = path.join(packagePath, 'package.json');
-  const {main} = await fs.readJSON(packageJsonPath);
+  const {main} = (await fs.readJSON(packageJsonPath)) as {main: string};
   const packageSrcPath = path.join(packagePath, path.dirname(main));
   return packageSrcPath;
 }
diff --git a/packages/docusaurus-utils-validation/src/JoiFrontMatter.ts b/packages/docusaurus-utils-validation/src/JoiFrontMatter.ts
index 011bccd8796c..b09f528ec14d 100644
--- a/packages/docusaurus-utils-validation/src/JoiFrontMatter.ts
+++ b/packages/docusaurus-utils-validation/src/JoiFrontMatter.ts
@@ -11,7 +11,7 @@ const JoiFrontMatterString: Joi.Extension = {
   type: 'string',
   base: Joi.string(),
   // Fix Yaml that tries to auto-convert many things to string out of the box
-  prepare: (value) => {
+  prepare: (value: unknown) => {
     if (typeof value === 'number' || value instanceof Date) {
       return {value: value.toString()};
     }
diff --git a/packages/docusaurus-utils-validation/src/validationSchemas.ts b/packages/docusaurus-utils-validation/src/validationSchemas.ts
index eea887bea2a5..8c6a10e9c00b 100644
--- a/packages/docusaurus-utils-validation/src/validationSchemas.ts
+++ b/packages/docusaurus-utils-validation/src/validationSchemas.ts
@@ -40,10 +40,10 @@ export const URISchema = Joi.alternatives(
   Joi.string().uri({allowRelative: true}),
   // This custom validation logic is required notably because Joi does not
   // accept paths like /a/b/c ...
-  Joi.custom((val, helpers) => {
+  Joi.custom((val: unknown, helpers) => {
     try {
       // eslint-disable-next-line no-new
-      new URL(val);
+      new URL(String(val));
       return val;
     } catch {
       return helpers.error('any.invalid');
@@ -55,7 +55,7 @@ export const URISchema = Joi.alternatives(
 });
 
 export const PathnameSchema = Joi.string()
-  .custom((val) => {
+  .custom((val: string) => {
     if (!isValidPathname(val)) {
       throw new Error();
     }
diff --git a/packages/docusaurus-utils/src/constants.ts b/packages/docusaurus-utils/src/constants.ts
index a9a91394f48c..be9405eab9bd 100644
--- a/packages/docusaurus-utils/src/constants.ts
+++ b/packages/docusaurus-utils/src/constants.ts
@@ -17,8 +17,9 @@ export const NODE_MINOR_VERSION = parseInt(
 );
 
 /** Docusaurus core version. */
-// eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
-export const DOCUSAURUS_VERSION = require('../package.json').version;
+export const DOCUSAURUS_VERSION =
+  // eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
+  (require('../package.json') as {version: string}).version;
 
 /**
  * Can be overridden with cli option `--out-dir`. Code should generally use
diff --git a/packages/docusaurus-utils/src/markdownUtils.ts b/packages/docusaurus-utils/src/markdownUtils.ts
index a902c6f58fa0..fd11f5e66708 100644
--- a/packages/docusaurus-utils/src/markdownUtils.ts
+++ b/packages/docusaurus-utils/src/markdownUtils.ts
@@ -280,7 +280,10 @@ This can happen if you use special characters in front matter values (try using
 }
 
 function unwrapMarkdownLinks(line: string): string {
-  return line.replace(/\[(?<alt>[^\]]+)\]\([^)]+\)/g, (match, p1) => p1);
+  return line.replace(
+    /\[(?<alt>[^\]]+)\]\([^)]+\)/g,
+    (match, p1: string) => p1,
+  );
 }
 
 function addHeadingId(
diff --git a/packages/docusaurus/src/babel/preset.ts b/packages/docusaurus/src/babel/preset.ts
index 3dd351ef9ac5..3d842007757e 100644
--- a/packages/docusaurus/src/babel/preset.ts
+++ b/packages/docusaurus/src/babel/preset.ts
@@ -53,7 +53,8 @@ function getTransformOptions(isServer: boolean): TransformOptions {
           // better to explicitly specify the version so that it can reuse the
           // helper better. See https://github.com/babel/babel/issues/10261
           // eslint-disable-next-line @typescript-eslint/no-var-requires, global-require
-          version: require('@babel/runtime/package.json').version,
+          version: (require('@babel/runtime/package.json') as {version: string})
+            .version,
           regenerator: true,
           useESModules: true,
           // Undocumented option that lets us encapsulate our runtime, ensuring
diff --git a/packages/docusaurus/src/client/PendingNavigation.tsx b/packages/docusaurus/src/client/PendingNavigation.tsx
index 3c2cca17f7b8..24e1e38faa2d 100644
--- a/packages/docusaurus/src/client/PendingNavigation.tsx
+++ b/packages/docusaurus/src/client/PendingNavigation.tsx
@@ -70,7 +70,7 @@ class PendingNavigation extends React.Component<Props, State> {
         this.routeUpdateCleanupCb?.();
         this.setState({nextRouteHasLoaded: true});
       })
-      .catch((e) => console.warn(e));
+      .catch((e: unknown) => console.warn(e));
     return false;
   }
 
diff --git a/packages/docusaurus/src/client/preload.ts b/packages/docusaurus/src/client/preload.ts
index e77ac998f58d..fec374ad4b6b 100644
--- a/packages/docusaurus/src/client/preload.ts
+++ b/packages/docusaurus/src/client/preload.ts
@@ -19,8 +19,5 @@ import {matchRoutes} from 'react-router-config';
 export default function preload(pathname: string): Promise<void[]> {
   const matches = matchRoutes(routes, pathname);
 
-  return Promise.all(
-    // @ts-expect-error: ComponentCreator injected this method.
-    matches.map((match) => match.route.component?.preload?.()),
-  );
+  return Promise.all(matches.map((match) => match.route.component.preload?.()));
 }
diff --git a/packages/docusaurus/src/client/theme-fallback/Loading/index.tsx b/packages/docusaurus/src/client/theme-fallback/Loading/index.tsx
index 79a0823c3194..7d47419bb7b3 100644
--- a/packages/docusaurus/src/client/theme-fallback/Loading/index.tsx
+++ b/packages/docusaurus/src/client/theme-fallback/Loading/index.tsx
@@ -37,7 +37,7 @@ export default function Loading({
           maxWidth: '50%',
           width: '100%',
         }}>
-        <p>{error.message}</p>
+        <p>{String(error)}</p>
         <div>
           <button type="button" onClick={retry}>
             Retry
diff --git a/packages/docusaurus/src/commands/start.ts b/packages/docusaurus/src/commands/start.ts
index a9e4e1e11e39..a0cae8416493 100644
--- a/packages/docusaurus/src/commands/start.ts
+++ b/packages/docusaurus/src/commands/start.ts
@@ -78,7 +78,7 @@ export async function start(
           logger.success`Docusaurus website is running at url=${newOpenUrl}.`;
         }
       })
-      .catch((err) => {
+      .catch((err: Error) => {
         logger.error(err.stack);
       });
   }, 500);
diff --git a/packages/docusaurus/src/commands/swizzle/prompts.ts b/packages/docusaurus/src/commands/swizzle/prompts.ts
index 6aa1d1e0e9f6..35d85e33875d 100644
--- a/packages/docusaurus/src/commands/swizzle/prompts.ts
+++ b/packages/docusaurus/src/commands/swizzle/prompts.ts
@@ -14,14 +14,14 @@ import type {SwizzleAction, SwizzleComponentConfig} from '@docusaurus/types';
 const ExitTitle = logger.yellow('[Exit]');
 
 export async function askThemeName(themeNames: string[]): Promise<string> {
-  const {themeName} = await prompts({
+  const {themeName} = (await prompts({
     type: 'select',
     name: 'themeName',
     message: 'Select a theme to swizzle:',
     choices: themeNames
       .map((theme) => ({title: theme, value: theme}))
       .concat({title: ExitTitle, value: '[Exit]'}),
-  });
+  })) as {themeName?: string};
   if (!themeName || themeName === '[Exit]') {
     process.exit(0);
   }
@@ -41,7 +41,7 @@ export async function askComponentName(
     })}`;
   }
 
-  const {componentName} = await prompts({
+  const {componentName} = (await prompts({
     type: 'autocomplete',
     name: 'componentName',
     message: `
@@ -58,12 +58,12 @@ ${PartiallySafeHint} = not safe for all swizzle actions
         value: compName,
       }))
       .concat({title: ExitTitle, value: '[Exit]'}),
-    async suggest(input, choices) {
+    async suggest(input: string, choices) {
       return choices.filter((choice) =>
         choice.title.toLowerCase().includes(input.toLowerCase()),
       );
     },
-  });
+  })) as {componentName?: string};
   logger.newLine();
 
   if (!componentName || componentName === '[Exit]') {
@@ -74,7 +74,7 @@ ${PartiallySafeHint} = not safe for all swizzle actions
 }
 
 export async function askSwizzleDangerousComponent(): Promise<boolean> {
-  const {switchToDanger} = await prompts({
+  const {switchToDanger} = (await prompts({
     type: 'select',
     name: 'switchToDanger',
     message: `Do you really want to swizzle this unsafe internal component?`,
@@ -86,7 +86,7 @@ export async function askSwizzleDangerousComponent(): Promise<boolean> {
       },
       {title: ExitTitle, value: '[Exit]'},
     ],
-  });
+  })) as {switchToDanger?: boolean | '[Exit]'};
 
   if (typeof switchToDanger === 'undefined' || switchToDanger === '[Exit]') {
     return process.exit(0);
@@ -98,7 +98,7 @@ export async function askSwizzleDangerousComponent(): Promise<boolean> {
 export async function askSwizzleAction(
   componentConfig: SwizzleComponentConfig,
 ): Promise<SwizzleAction> {
-  const {action} = await prompts({
+  const {action} = (await prompts({
     type: 'select',
     name: 'action',
     message: `Which swizzle action do you want to do?`,
@@ -117,7 +117,7 @@ export async function askSwizzleAction(
       },
       {title: ExitTitle, value: '[Exit]'},
     ],
-  });
+  })) as {action?: SwizzleAction | '[Exit]'};
 
   if (typeof action === 'undefined' || action === '[Exit]') {
     return process.exit(0);
diff --git a/packages/docusaurus/src/server/config.ts b/packages/docusaurus/src/server/config.ts
index 13ab71215c25..73cccc613654 100644
--- a/packages/docusaurus/src/server/config.ts
+++ b/packages/docusaurus/src/server/config.ts
@@ -30,7 +30,7 @@ export async function loadSiteConfig({
 
   const importedConfig = importFresh(siteConfigPath);
 
-  const loadedConfig =
+  const loadedConfig: unknown =
     typeof importedConfig === 'function'
       ? await importedConfig()
       : await importedConfig;
diff --git a/packages/docusaurus/src/server/configValidation.ts b/packages/docusaurus/src/server/configValidation.ts
index d1c009ae66dd..2820e4b44dc3 100644
--- a/packages/docusaurus/src/server/configValidation.ts
+++ b/packages/docusaurus/src/server/configValidation.ts
@@ -144,9 +144,9 @@ const I18N_CONFIG_SCHEMA = Joi.object<I18nConfig>({
   .optional()
   .default(DEFAULT_I18N_CONFIG);
 
-const SiteUrlSchema = URISchema.required().custom((value, helpers) => {
+const SiteUrlSchema = URISchema.required().custom((value: unknown, helpers) => {
   try {
-    const {pathname} = new URL(value);
+    const {pathname} = new URL(String(value));
     if (pathname !== '/') {
       helpers.warn('docusaurus.configValidationWarning', {
         warningMessage: `the url is not supposed to contain a sub-path like '${pathname}', please use the baseUrl field for sub-paths`,
@@ -157,7 +157,7 @@ const SiteUrlSchema = URISchema.required().custom((value, helpers) => {
 }, 'siteUrlCustomValidation');
 
 // TODO move to @docusaurus/utils-validation
-export const ConfigSchema = Joi.object({
+export const ConfigSchema = Joi.object<DocusaurusConfig>({
   baseUrl: Joi.string()
     .required()
     .regex(/\/$/m)
@@ -237,9 +237,7 @@ export const ConfigSchema = Joi.object({
 });
 
 // TODO move to @docusaurus/utils-validation
-export function validateConfig(
-  config: Partial<DocusaurusConfig>,
-): DocusaurusConfig {
+export function validateConfig(config: unknown): DocusaurusConfig {
   const {error, warning, value} = ConfigSchema.validate(config, {
     abortEarly: false,
   });
diff --git a/packages/docusaurus/src/server/getHostPort.ts b/packages/docusaurus/src/server/getHostPort.ts
index 40960bdfff9a..4ae80708704f 100644
--- a/packages/docusaurus/src/server/getHostPort.ts
+++ b/packages/docusaurus/src/server/getHostPort.ts
@@ -70,7 +70,7 @@ async function choosePort(
     }
     clearConsole();
     const existingProcess = getProcessForPort(defaultPort);
-    const {shouldChangePort} = await prompts({
+    const {shouldChangePort} = (await prompts({
       type: 'confirm',
       name: 'shouldChangePort',
       message: logger.yellow(`${logger.bold('[WARNING]')} ${message}${
@@ -79,7 +79,7 @@ async function choosePort(
 
 Would you like to run the app on another port instead?`),
       initial: true,
-    });
+    })) as {shouldChangePort: boolean};
     return shouldChangePort ? port : null;
   } catch (err) {
     logger.error`Could not find an open port at ${host}.`;
diff --git a/packages/docusaurus/src/server/siteMetadata.ts b/packages/docusaurus/src/server/siteMetadata.ts
index b442eed15292..affcbf7183ec 100644
--- a/packages/docusaurus/src/server/siteMetadata.ts
+++ b/packages/docusaurus/src/server/siteMetadata.ts
@@ -20,7 +20,7 @@ async function getPackageJsonVersion(
 ): Promise<string | undefined> {
   if (await fs.pathExists(packageJsonPath)) {
     // eslint-disable-next-line @typescript-eslint/no-var-requires, import/no-dynamic-require, global-require
-    return require(packageJsonPath).version;
+    return (require(packageJsonPath) as {version?: string}).version;
   }
   return undefined;
 }
@@ -29,7 +29,7 @@ async function getPackageJsonName(
   packageJsonPath: string,
 ): Promise<string | undefined> {
   // eslint-disable-next-line @typescript-eslint/no-var-requires, import/no-dynamic-require, global-require
-  return require(packageJsonPath).name;
+  return (require(packageJsonPath) as {name?: string}).name;
 }
 
 export async function getPluginVersion(
diff --git a/packages/docusaurus/src/server/translations/translations.ts b/packages/docusaurus/src/server/translations/translations.ts
index fcbe5f5e1184..fd3fb0305523 100644
--- a/packages/docusaurus/src/server/translations/translations.ts
+++ b/packages/docusaurus/src/server/translations/translations.ts
@@ -58,7 +58,7 @@ async function readTranslationFileContent(
 ): Promise<TranslationFileContent | undefined> {
   if (await fs.pathExists(filePath)) {
     try {
-      const content = await fs.readJSON(filePath);
+      const content: unknown = await fs.readJSON(filePath);
       ensureTranslationFileContent(content);
       return content;
     } catch (err) {
diff --git a/packages/docusaurus/src/server/translations/translationsExtractor.ts b/packages/docusaurus/src/server/translations/translationsExtractor.ts
index 569c3314b112..6113b23ba933 100644
--- a/packages/docusaurus/src/server/translations/translationsExtractor.ts
+++ b/packages/docusaurus/src/server/translations/translationsExtractor.ts
@@ -347,10 +347,12 @@ ${sourceWarningPart(path.node)}`,
             firstArgEvaluated.confident &&
             typeof firstArgEvaluated.value === 'object'
           ) {
-            const {message, id, description} = firstArgEvaluated.value;
-            translations[id ?? message] = {
-              message: message ?? id,
-              ...(description && {description}),
+            const {message, id, description} = firstArgEvaluated.value as {
+              [propName: string]: unknown;
+            };
+            translations[String(id ?? message)] = {
+              message: String(message ?? id),
+              ...(Boolean(description) && {description: String(description)}),
             };
           } else {
             warnings.push(
diff --git a/packages/lqip-loader/package.json b/packages/lqip-loader/package.json
index b06ff7780520..5e96bac253fe 100644
--- a/packages/lqip-loader/package.json
+++ b/packages/lqip-loader/package.json
@@ -27,6 +27,7 @@
     "node": ">=14"
   },
   "devDependencies": {
+    "@types/file-loader": "^5.0.1",
     "@types/sharp": "^0.30.2"
   }
 }
diff --git a/packages/lqip-loader/src/index.ts b/packages/lqip-loader/src/index.ts
index 112851a34c01..6bb0eb526240 100644
--- a/packages/lqip-loader/src/index.ts
+++ b/packages/lqip-loader/src/index.ts
@@ -38,7 +38,7 @@ export default async function lqipLoader(
   } else {
     if (!contentIsFileExport) {
       // eslint-disable-next-line global-require, @typescript-eslint/no-var-requires
-      const fileLoader = require('file-loader');
+      const fileLoader = require('file-loader') as typeof import('file-loader');
       content = fileLoader.call(this, contentBuffer);
     }
     source = content.match(
diff --git a/packages/lqip-loader/src/lqip.ts b/packages/lqip-loader/src/lqip.ts
index c26956f19e9c..929e53ba6a9e 100644
--- a/packages/lqip-loader/src/lqip.ts
+++ b/packages/lqip-loader/src/lqip.ts
@@ -9,8 +9,8 @@ import path from 'path';
 import logger from '@docusaurus/logger';
 import sharp from 'sharp';
 
-// eslint-disable-next-line @typescript-eslint/no-var-requires
-const {version} = require('../package.json');
+// eslint-disable-next-line @typescript-eslint/no-var-requires, global-require
+const {version} = require('../package.json') as {version: string};
 
 const ERROR_EXT = `Error: Input file is missing or uses unsupported image format, lqip v${version}`;
 
diff --git a/website/community/4-canary/Versions.tsx b/website/community/4-canary/Versions.tsx
index a36907b10cf4..c227a9094e7a 100644
--- a/website/community/4-canary/Versions.tsx
+++ b/website/community/4-canary/Versions.tsx
@@ -27,11 +27,13 @@ export function VersionsProvider({
   useEffect(() => {
     fetch('https://registry.npmjs.org/@docusaurus/core')
       .then((res) => res.json())
-      .then((data) => {
-        const name = Object.keys(data.versions).at(-1)!;
-        const time = data.time[name];
-        setCanaryVersion({name, time});
-      });
+      .then(
+        (data: {versions: string[]; time: {[versionName: string]: string}}) => {
+          const name = Object.keys(data.versions).at(-1)!;
+          const time = data.time[name];
+          setCanaryVersion({name, time});
+        },
+      );
   }, []);
   return <Context.Provider value={canaryVersion}>{children}</Context.Provider>;
 }
diff --git a/yarn.lock b/yarn.lock
index d72e94dfefcb..4c52edca54a9 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3308,6 +3308,13 @@
     "@types/qs" "*"
     "@types/serve-static" "*"
 
+"@types/file-loader@^5.0.1":
+  version "5.0.1"
+  resolved "https://registry.yarnpkg.com/@types/file-loader/-/file-loader-5.0.1.tgz#300b7c729e4f0c523783b865b287e3459135bf22"
+  integrity sha512-FHPPuRb/Ts/25qvNU/mQGwRZUp793nBxYqXd/KwApykxATagqrO4+2EEcGDm/DuXyV/EkOa04umS1DQ8tQSomg==
+  dependencies:
+    "@types/webpack" "^4"
+
 "@types/fs-extra@^9.0.13":
   version "9.0.13"
   resolved "https://registry.yarnpkg.com/@types/fs-extra/-/fs-extra-9.0.13.tgz#7594fbae04fe7f1918ce8b3d213f74ff44ac1f45"