diff --git a/src/libs/Navigation/guards/OnboardingGuard.ts b/src/libs/Navigation/guards/OnboardingGuard.ts
index c7a731798167..1a2960ca9a81 100644
--- a/src/libs/Navigation/guards/OnboardingGuard.ts
+++ b/src/libs/Navigation/guards/OnboardingGuard.ts
@@ -150,7 +150,9 @@ function isCurrentlyOnTwoFactorSetupRoute(state: NavigationState): boolean {
 }
 
 function shouldPreventReset(state: NavigationState, action: NavigationAction) {
-    if (action.type !== CONST.NAVIGATION_ACTIONS.RESET || !action?.payload) {
+    // Browser back that pops the last history entry dispatches GO_BACK instead of RESET, and it reaches the root only when it would leave onboarding
+    const isGoBack = action.type === CONST.NAVIGATION.ACTION_TYPE.GO_BACK;
+    if (!isGoBack && (action.type !== CONST.NAVIGATION_ACTIONS.RESET || !action?.payload)) {
         return false;
     }
 
diff --git a/tests/unit/Navigation/guards/OnboardingGuard.test.ts b/tests/unit/Navigation/guards/OnboardingGuard.test.ts
index 990fa7d497ad..5dfcb87f27e0 100644
--- a/tests/unit/Navigation/guards/OnboardingGuard.test.ts
+++ b/tests/unit/Navigation/guards/OnboardingGuard.test.ts
@@ -139,6 +139,24 @@ describe('OnboardingGuard', () => {
                 expect(result.reason).toBe('Cannot reset to non-onboarding screen while on onboarding');
             }
         });
+
+        it('should BLOCK GO_BACK action when user is on onboarding', () => {
+            // Given a user who is currently on the onboarding purpose screen and has not yet completed onboarding
+            const onboardingState: NavigationState = {
+                key: 'root',
+                index: 0,
+                routeNames: [SCREENS.ONBOARDING.PURPOSE],
+                routes: [{key: 'purpose', name: SCREENS.ONBOARDING.PURPOSE}],
+                stale: false,
+                type: 'root',
+            };
+
+            // When the browser back button pops the last history entry, which React Navigation dispatches as GO_BACK
+            const result = OnboardingGuard.evaluate(onboardingState, {type: CONST.NAVIGATION.ACTION_TYPE.GO_BACK}, authenticatedContext);
+
+            // Then the action should be blocked because going back from onboarding would close the modal without finishing it
+            expect(result.type).toBe('BLOCK');
+        });
     });
 
     describe('skip onboarding conditions', () => {