diff --git a/app/brave_main_delegate.cc b/app/brave_main_delegate.cc
index d28d6dc65664..8a4273c68b4e 100644
--- a/app/brave_main_delegate.cc
+++ b/app/brave_main_delegate.cc
@@ -151,6 +151,9 @@ bool BraveMainDelegate::BasicStartupComplete(int* exit_code) {
 
   command_line.AppendSwitch(switches::kDisableDatabases);
 
+  // Disable sync temporarily
+  command_line.AppendSwitch(switches::kDisableSync);
+
   // Enabled features.
   const std::unordered_set<const char*> enabled_features = {
       password_manager::features::kPasswordImport.name,
diff --git a/browser/brave_content_browser_client_browsertest.cc b/browser/brave_content_browser_client_browsertest.cc
index a8185f8cd2de..f897f8ecc679 100644
--- a/browser/brave_content_browser_client_browsertest.cc
+++ b/browser/brave_content_browser_client_browsertest.cc
@@ -27,6 +27,7 @@
 #include "chrome/test/base/ui_test_utils.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/prefs/pref_service.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/test/browser_test_utils.h"
 #include "content/public/test/test_navigation_observer.h"
@@ -154,10 +155,11 @@ IN_PROC_BROWSER_TEST_F(BraveContentBrowserClientTest, CanLoadCustomBravePages) {
 #if BUILDFLAG(BRAVE_REWARDS_ENABLED)
         "rewards",
 #endif
+  };
 #if BUILDFLAG(ENABLE_BRAVE_SYNC)
-        chrome::kChromeUISyncHost,
+  if (switches::IsSyncAllowedByFlag())
+    pages.push_back(chrome::kChromeUISyncHost);
 #endif
-  };
 
   std::vector<std::string> schemes {
     "brave://",
@@ -221,7 +223,10 @@ IN_PROC_BROWSER_TEST_F(BraveContentBrowserClientTest,
         browser()->tab_strip_model()->GetActiveWebContents();
     ui_test_utils::NavigateToURL(
         browser(), GURL(scheme + chrome::kChromeUISyncInternalsHost));
-    ASSERT_TRUE(WaitForLoadStop(contents));
+    if (switches::IsSyncAllowedByFlag())
+      ASSERT_TRUE(WaitForLoadStop(contents));
+    else
+      ASSERT_FALSE(WaitForLoadStop(contents));
 
     EXPECT_STREQ(base::UTF16ToUTF8(browser()->location_bar_model()
                     ->GetFormattedFullURL()).c_str(),
diff --git a/browser/ui/brave_browser_command_controller_browsertest.cc b/browser/ui/brave_browser_command_controller_browsertest.cc
index 778d2297b296..aaeeaf2766f3 100644
--- a/browser/ui/brave_browser_command_controller_browsertest.cc
+++ b/browser/ui/brave_browser_command_controller_browsertest.cc
@@ -19,6 +19,7 @@
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/test/base/in_process_browser_test.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/test/test_utils.h"
 
@@ -53,7 +54,10 @@ IN_PROC_BROWSER_TEST_F(BraveBrowserCommandControllerTest,
 #endif
 
 #if BUILDFLAG(ENABLE_BRAVE_SYNC)
-  EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  if (switches::IsSyncAllowedByFlag())
+    EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  else
+    EXPECT_FALSE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
 #else
   EXPECT_FALSE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
 #endif
@@ -86,7 +90,10 @@ IN_PROC_BROWSER_TEST_F(BraveBrowserCommandControllerTest,
 #endif
 
 #if BUILDFLAG(ENABLE_BRAVE_SYNC)
-  EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  if (switches::IsSyncAllowedByFlag())
+    EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  else
+    EXPECT_FALSE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
 #endif
 
 #if BUILDFLAG(BRAVE_WALLET_ENABLED)
@@ -171,7 +178,10 @@ IN_PROC_BROWSER_TEST_F(BraveBrowserCommandControllerTest,
 #endif
 
 #if BUILDFLAG(ENABLE_BRAVE_SYNC)
-  EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  if (switches::IsSyncAllowedByFlag())
+    EXPECT_TRUE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
+  else
+    EXPECT_FALSE(command_controller->IsCommandEnabled(IDC_SHOW_BRAVE_SYNC));
 #endif
 
 #if BUILDFLAG(BRAVE_WALLET_ENABLED)
diff --git a/browser/ui/toolbar/brave_app_menu_model_browsertest.cc b/browser/ui/toolbar/brave_app_menu_model_browsertest.cc
index 41af60d884ca..2eb93b8e80bf 100644
--- a/browser/ui/toolbar/brave_app_menu_model_browsertest.cc
+++ b/browser/ui/toolbar/brave_app_menu_model_browsertest.cc
@@ -23,6 +23,7 @@
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/toolbar/toolbar_view.h"
 #include "chrome/test/base/in_process_browser_test.h"
+#include "components/sync/driver/sync_driver_switches.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/test/test_utils.h"
 
@@ -88,6 +89,16 @@ IN_PROC_BROWSER_TEST_F(BraveAppMenuBrowserTest, MenuOrderTest) {
   std::vector<int> commands_disabled_for_normal_profile = {
     IDC_NEW_TOR_CONNECTION_FOR_SITE,
   };
+#if BUILDFLAG(ENABLE_BRAVE_SYNC)
+  if (!switches::IsSyncAllowedByFlag()) {
+    commands_in_order_for_normal_profile.erase(
+        std::remove(commands_in_order_for_normal_profile.begin(),
+                    commands_in_order_for_normal_profile.end(),
+                    IDC_SHOW_BRAVE_SYNC),
+        commands_in_order_for_normal_profile.end());
+    commands_disabled_for_normal_profile.push_back(IDC_SHOW_BRAVE_SYNC);
+  }
+#endif
   CheckCommandsAreInOrderInMenuModel(browser(),
                                      commands_in_order_for_normal_profile);
   CheckCommandsAreDisabledInMenuModel(browser(),
@@ -122,6 +133,16 @@ IN_PROC_BROWSER_TEST_F(BraveAppMenuBrowserTest, MenuOrderTest) {
     IDC_NEW_TOR_CONNECTION_FOR_SITE,
     IDC_RECENT_TABS_MENU,
   };
+#if BUILDFLAG(ENABLE_BRAVE_SYNC)
+  if (!switches::IsSyncAllowedByFlag()) {
+    commands_in_order_for_private_profile.erase(
+        std::remove(commands_in_order_for_private_profile.begin(),
+                    commands_in_order_for_private_profile.end(),
+                    IDC_SHOW_BRAVE_SYNC),
+        commands_in_order_for_private_profile.end());
+    commands_disabled_for_private_profile.push_back(IDC_SHOW_BRAVE_SYNC);
+  }
+#endif
   CheckCommandsAreInOrderInMenuModel(private_browser,
                                      commands_in_order_for_private_profile);
   CheckCommandsAreDisabledInMenuModel(private_browser,
@@ -215,6 +236,16 @@ IN_PROC_BROWSER_TEST_F(BraveAppMenuBrowserTest, MenuOrderTest) {
   std::vector<int> commands_disabled_for_tor_profile = {
     IDC_RECENT_TABS_MENU,
   };
+#if BUILDFLAG(ENABLE_BRAVE_SYNC)
+  if (!switches::IsSyncAllowedByFlag()) {
+    commands_in_order_for_tor_profile.erase(
+        std::remove(commands_in_order_for_tor_profile.begin(),
+                    commands_in_order_for_tor_profile.end(),
+                    IDC_SHOW_BRAVE_SYNC),
+        commands_in_order_for_tor_profile.end());
+    commands_disabled_for_tor_profile.push_back(IDC_SHOW_BRAVE_SYNC);
+  }
+#endif
   CheckCommandsAreInOrderInMenuModel(tor_browser,
                                      commands_in_order_for_tor_profile);
   CheckCommandsAreDisabledInMenuModel(tor_browser,