diff --git a/src/App.tsx b/src/App.tsx
index cbe5948f8d4e..0e247d5faa53 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -83,7 +83,6 @@ function App({url}: AppProps) {
                     <CustomStatusBarAndBackground />
                     <ErrorBoundary errorMessage="NewExpensify crash caught by error boundary">
                         <ColorSchemeWrapper>
-                            {/* @ts-expect-error TODO: Remove this once Expensify (https://github.com/Expensify/App/issues/25231) is migrated to TypeScript. */}
                             <Expensify />
                         </ColorSchemeWrapper>
                     </ErrorBoundary>
diff --git a/src/Expensify.js b/src/Expensify.tsx
similarity index 64%
rename from src/Expensify.js
rename to src/Expensify.tsx
index dfb59a0f8848..f822862ec434 100644
--- a/src/Expensify.js
+++ b/src/Expensify.tsx
@@ -1,9 +1,8 @@
-import lodashGet from 'lodash/get';
-import PropTypes from 'prop-types';
 import React, {useCallback, useEffect, useLayoutEffect, useMemo, useRef, useState} from 'react';
+import type {NativeEventSubscription} from 'react-native';
 import {AppState, Linking} from 'react-native';
+import type {OnyxEntry} from 'react-native-onyx';
 import Onyx, {withOnyx} from 'react-native-onyx';
-import _ from 'underscore';
 import ConfirmModal from './components/ConfirmModal';
 import DeeplinkWrapper from './components/DeeplinkWrapper';
 import EmojiPicker from './components/EmojiPicker/EmojiPicker';
@@ -12,14 +11,13 @@ import GrowlNotification from './components/GrowlNotification';
 import AppleAuthWrapper from './components/SignInButtons/AppleAuthWrapper';
 import SplashScreenHider from './components/SplashScreenHider';
 import UpdateAppModal from './components/UpdateAppModal';
-import withLocalize, {withLocalizePropTypes} from './components/withLocalize';
 import CONST from './CONST';
+import useLocalize from './hooks/useLocalize';
 import * as EmojiPickerAction from './libs/actions/EmojiPickerAction';
 import * as Report from './libs/actions/Report';
 import * as User from './libs/actions/User';
 import * as ActiveClientManager from './libs/ActiveClientManager';
 import BootSplash from './libs/BootSplash';
-import compose from './libs/compose';
 import * as Growl from './libs/Growl';
 import Log from './libs/Log';
 import migrateOnyx from './libs/migrateOnyx';
@@ -27,16 +25,18 @@ import Navigation from './libs/Navigation/Navigation';
 import NavigationRoot from './libs/Navigation/NavigationRoot';
 import NetworkConnection from './libs/NetworkConnection';
 import PushNotification from './libs/Notification/PushNotification';
-// eslint-disable-next-line no-unused-vars
-import subscribePushNotification from './libs/Notification/PushNotification/subscribePushNotification';
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+import './libs/Notification/PushNotification/subscribePushNotification';
 import StartupTimer from './libs/StartupTimer';
 // This lib needs to be imported, but it has nothing to export since all it contains is an Onyx connection
-// eslint-disable-next-line no-unused-vars
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
 import UnreadIndicatorUpdater from './libs/UnreadIndicatorUpdater';
 import Visibility from './libs/Visibility';
 import ONYXKEYS from './ONYXKEYS';
 import PopoverReportActionContextMenu from './pages/home/report/ContextMenu/PopoverReportActionContextMenu';
 import * as ReportActionContextMenu from './pages/home/report/ContextMenu/ReportActionContextMenu';
+import type {Route} from './ROUTES';
+import type {ScreenShareRequest, Session} from './types/onyx';
 
 Onyx.registerLogger(({level, message}) => {
     if (level === 'alert') {
@@ -47,82 +47,63 @@ Onyx.registerLogger(({level, message}) => {
     }
 });
 
-const propTypes = {
-    /* Onyx Props */
+type ExpensifyOnyxProps = {
+    /** Whether the app is waiting for the server's response to determine if a room is public */
+    isCheckingPublicRoom: OnyxEntry<boolean>;
 
     /** Session info for the currently logged in user. */
-    session: PropTypes.shape({
-        /** Currently logged in user authToken */
-        authToken: PropTypes.string,
-
-        /** Currently logged in user accountID */
-        accountID: PropTypes.number,
-    }),
+    session: OnyxEntry<Session>;
 
     /** Whether a new update is available and ready to install. */
-    updateAvailable: PropTypes.bool,
+    updateAvailable: OnyxEntry<boolean>;
 
-    /** Tells us if the sidebar has rendered - TODO: We don't use it as temporary solution to fix not hidding splashscreen */
-    // eslint-disable-next-line react/no-unused-prop-types
-    isSidebarLoaded: PropTypes.bool,
+    /** Tells us if the sidebar has rendered */
+    isSidebarLoaded: OnyxEntry<boolean>;
 
     /** Information about a screen share call requested by a GuidesPlus agent */
-    screenShareRequest: PropTypes.shape({
-        /** Access token required to join a screen share room, generated by the backend */
-        accessToken: PropTypes.string,
-
-        /** Name of the screen share room to join */
-        roomName: PropTypes.string,
-    }),
-
-    /** Whether the app is waiting for the server's response to determine if a room is public */
-    isCheckingPublicRoom: PropTypes.bool,
+    screenShareRequest: OnyxEntry<ScreenShareRequest>;
 
     /** True when the user must update to the latest minimum version of the app */
-    updateRequired: PropTypes.bool,
+    updateRequired: OnyxEntry<boolean>;
 
     /** Whether we should display the notification alerting the user that focus mode has been auto-enabled */
-    focusModeNotification: PropTypes.bool,
+    focusModeNotification: OnyxEntry<boolean>;
 
     /** Last visited path in the app */
-    lastVisitedPath: PropTypes.string,
-
-    ...withLocalizePropTypes,
+    lastVisitedPath: OnyxEntry<string | undefined>;
 };
 
-const defaultProps = {
-    session: {
-        authToken: null,
-        accountID: null,
-    },
-    updateAvailable: false,
-    isSidebarLoaded: false,
-    screenShareRequest: null,
-    isCheckingPublicRoom: true,
-    updateRequired: false,
-    focusModeNotification: false,
-    lastVisitedPath: undefined,
-};
+type ExpensifyProps = ExpensifyOnyxProps;
 
 const SplashScreenHiddenContext = React.createContext({});
 
-function Expensify(props) {
-    const appStateChangeListener = useRef(null);
+function Expensify({
+    isCheckingPublicRoom = true,
+    session,
+    updateAvailable,
+    isSidebarLoaded = false,
+    screenShareRequest,
+    updateRequired = false,
+    focusModeNotification = false,
+    lastVisitedPath,
+}: ExpensifyProps) {
+    const appStateChangeListener = useRef<NativeEventSubscription | null>(null);
     const [isNavigationReady, setIsNavigationReady] = useState(false);
     const [isOnyxMigrated, setIsOnyxMigrated] = useState(false);
     const [isSplashHidden, setIsSplashHidden] = useState(false);
     const [hasAttemptedToOpenPublicRoom, setAttemptedToOpenPublicRoom] = useState(false);
-    const [initialUrl, setInitialUrl] = useState(null);
+    const {translate} = useLocalize();
+    const [initialUrl, setInitialUrl] = useState<string | null>(null);
 
     useEffect(() => {
-        if (props.isCheckingPublicRoom) {
+        if (isCheckingPublicRoom) {
             return;
         }
         setAttemptedToOpenPublicRoom(true);
-    }, [props.isCheckingPublicRoom]);
+    }, [isCheckingPublicRoom]);
 
-    const isAuthenticated = useMemo(() => Boolean(lodashGet(props.session, 'authToken', null)), [props.session]);
-    const autoAuthState = useMemo(() => lodashGet(props.session, 'autoAuthState', ''), [props.session]);
+    const isAuthenticated = useMemo(() => !!(session?.authToken ?? null), [session]);
+    const autoAuthState = useMemo(() => session?.autoAuthState ?? '', [session]);
 
     const contextValue = useMemo(
         () => ({
@@ -168,8 +149,16 @@ function Expensify(props) {
                 Log.info('[BootSplash] splash screen status', false, {appState, status});
 
                 if (status === 'visible') {
-                    const propsToLog = _.omit(props, ['children', 'session']);
-                    propsToLog.isAuthenticated = isAuthenticated;
+                    const propsToLog: Omit<ExpensifyProps & {isAuthenticated: boolean}, 'children' | 'session'> = {
+                        isCheckingPublicRoom,
+                        updateRequired,
+                        updateAvailable,
+                        isSidebarLoaded,
+                        screenShareRequest,
+                        focusModeNotification,
+                        isAuthenticated,
+                        lastVisitedPath,
+                    };
                     Log.alert('[BootSplash] splash screen is still visible', {propsToLog}, false);
                 }
             });
@@ -194,7 +183,7 @@ function Expensify(props) {
         // If the app is opened from a deep link, get the reportID (if exists) from the deep link and navigate to the chat report
         Linking.getInitialURL().then((url) => {
             setInitialUrl(url);
-            Report.openReportFromDeepLink(url, isAuthenticated);
+            Report.openReportFromDeepLink(url ?? '', isAuthenticated);
         });
 
         // Open chat report from a deep link (only mobile native)
@@ -216,7 +205,7 @@ function Expensify(props) {
         return null;
     }
 
-    if (props.updateRequired) {
+    if (updateRequired) {
         throw new Error(CONST.ERROR.UPDATE_REQUIRED);
     }
 
@@ -231,20 +220,19 @@ function Expensify(props) {
                     <PopoverReportActionContextMenu ref={ReportActionContextMenu.contextMenuRef} />
                     <EmojiPicker ref={EmojiPickerAction.emojiPickerRef} />
                     {/* We include the modal for showing a new update at the top level so the option is always present. */}
-                    {/* If the update is required we won't show this option since a full screen update view will be displayed instead. */}
-                    {props.updateAvailable && !props.updateRequired ? <UpdateAppModal /> : null}
-                    {props.screenShareRequest ? (
+                    {updateAvailable && !updateRequired ? <UpdateAppModal /> : null}
+                    {screenShareRequest ? (
                         <ConfirmModal
-                            title={props.translate('guides.screenShare')}
-                            onConfirm={() => User.joinScreenShare(props.screenShareRequest.accessToken, props.screenShareRequest.roomName)}
+                            title={translate('guides.screenShare')}
+                            onConfirm={() => User.joinScreenShare(screenShareRequest.accessToken, screenShareRequest.roomName)}
                             onCancel={User.clearScreenShareRequest}
-                            prompt={props.translate('guides.screenShareRequest')}
-                            confirmText={props.translate('common.join')}
-                            cancelText={props.translate('common.decline')}
+                            prompt={translate('guides.screenShareRequest')}
+                            confirmText={translate('common.join')}
+                            cancelText={translate('common.decline')}
                             isVisible
                         />
                     ) : null}
-                    {props.focusModeNotification ? <FocusModeNotification /> : null}
+                    {focusModeNotification ? <FocusModeNotification /> : null}
                 </>
             )}
 
@@ -254,7 +242,7 @@ function Expensify(props) {
                     <NavigationRoot
                         onReady={setNavigationReady}
                         authenticated={isAuthenticated}
-                        lastVisitedPath={props.lastVisitedPath}
+                        lastVisitedPath={lastVisitedPath as Route}
                         initialUrl={initialUrl}
                     />
                 </SplashScreenHiddenContext.Provider>
@@ -265,40 +253,35 @@ function Expensify(props) {
     );
 }
 
-Expensify.propTypes = propTypes;
-Expensify.defaultProps = defaultProps;
-export default compose(
-    withLocalize,
-    withOnyx({
-        isCheckingPublicRoom: {
-            key: ONYXKEYS.IS_CHECKING_PUBLIC_ROOM,
-            initWithStoredValues: false,
-        },
-        session: {
-            key: ONYXKEYS.SESSION,
-        },
-        updateAvailable: {
-            key: ONYXKEYS.UPDATE_AVAILABLE,
-            initWithStoredValues: false,
-        },
-        isSidebarLoaded: {
-            key: ONYXKEYS.IS_SIDEBAR_LOADED,
-        },
-        screenShareRequest: {
-            key: ONYXKEYS.SCREEN_SHARE_REQUEST,
-        },
-        updateRequired: {
-            key: ONYXKEYS.UPDATE_REQUIRED,
-            initWithStoredValues: false,
-        },
-        focusModeNotification: {
-            key: ONYXKEYS.FOCUS_MODE_NOTIFICATION,
-            initWithStoredValues: false,
-        },
-        lastVisitedPath: {
-            key: ONYXKEYS.LAST_VISITED_PATH,
-        },
-    }),
-)(Expensify);
+export default withOnyx<ExpensifyProps, ExpensifyOnyxProps>({
+    isCheckingPublicRoom: {
+        key: ONYXKEYS.IS_CHECKING_PUBLIC_ROOM,
+        initWithStoredValues: false,
+    },
+    session: {
+        key: ONYXKEYS.SESSION,
+    },
+    updateAvailable: {
+        key: ONYXKEYS.UPDATE_AVAILABLE,
+        initWithStoredValues: false,
+    },
+    updateRequired: {
+        key: ONYXKEYS.UPDATE_REQUIRED,
+        initWithStoredValues: false,
+    },
+    isSidebarLoaded: {
+        key: ONYXKEYS.IS_SIDEBAR_LOADED,
+    },
+    screenShareRequest: {
+        key: ONYXKEYS.SCREEN_SHARE_REQUEST,
+    },
+    focusModeNotification: {
+        key: ONYXKEYS.FOCUS_MODE_NOTIFICATION,
+        initWithStoredValues: false,
+    },
+    lastVisitedPath: {
+        key: ONYXKEYS.LAST_VISITED_PATH,
+    },
+})(Expensify);
 
 export {SplashScreenHiddenContext};
diff --git a/src/pages/home/report/ContextMenu/PopoverReportActionContextMenu.tsx b/src/pages/home/report/ContextMenu/PopoverReportActionContextMenu.tsx
index 0b4154a15e80..47cbc559a67b 100644
--- a/src/pages/home/report/ContextMenu/PopoverReportActionContextMenu.tsx
+++ b/src/pages/home/report/ContextMenu/PopoverReportActionContextMenu.tsx
@@ -31,7 +31,7 @@ function extractPointerEvent(event: GestureResponderEvent | MouseEvent): MouseEv
 }
 
 // eslint-disable-next-line @typescript-eslint/naming-convention
-function PopoverReportActionContextMenu(_props: never, ref: ForwardedRef<ReportActionContextMenu>) {
+function PopoverReportActionContextMenu(_props: unknown, ref: ForwardedRef<ReportActionContextMenu>) {
     const {translate} = useLocalize();
     const reportIDRef = useRef('0');
     const typeRef = useRef<ContextMenuType>();