diff --git a/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.cc b/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.cc
index 3308c8bc53ad..59aa44049881 100644
--- a/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.cc
+++ b/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.cc
@@ -10,6 +10,7 @@
 #include "base/check.h"
 #include "brave/browser/ui/views/frame/brave_browser_view.h"
 #include "brave/browser/ui/views/frame/vertical_tab_strip_region_view.h"
+#include "brave/browser/ui/views/tabs/vertical_tab_utils.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
 #include "chrome/browser/ui/views/theme_copying_widget.h"
@@ -138,11 +139,15 @@ VerticalTabStripWidgetDelegateView::VerticalTabStripWidgetDelegateView(
   SetLayoutManager(std::make_unique<views::FillLayout>());
 
   host_view_observation_.Observe(host_);
-  widget_observation_.Observe(host_->GetWidget());
+  widget_observation_.AddObservation(host_->GetWidget());
 
   ChildPreferredSizeChanged(region_view_);
 }
 
+void VerticalTabStripWidgetDelegateView::AddedToWidget() {
+  widget_observation_.AddObservation(GetWidget());
+}
+
 void VerticalTabStripWidgetDelegateView::ChildPreferredSizeChanged(
     views::View* child) {
   if (!host_)
@@ -184,9 +189,27 @@ void VerticalTabStripWidgetDelegateView::OnViewIsDeleting(
   host_ = nullptr;
 }
 
+void VerticalTabStripWidgetDelegateView::OnWidgetVisibilityChanged(
+    views::Widget* widget,
+    bool visible) {
+  if (widget == GetWidget()) {
+    if (!tabs::utils::ShouldShowVerticalTabs(browser_view_->browser()) &&
+        visible) {
+      // This happens when restoring browser window. The upstream implementation
+      // make child widgets visible regardless of their previous visibility.
+      // https://github.com/brave/brave-browser/issues/29917
+      widget->Hide();
+    }
+  }
+}
+
 void VerticalTabStripWidgetDelegateView::OnWidgetBoundsChanged(
     views::Widget* widget,
     const gfx::Rect& new_bounds) {
+  if (widget == GetWidget()) {
+    return;
+  }
+
   // The parent widget could be resized because fullscreen status changed.
   // Try resetting preferred size.
   ChildPreferredSizeChanged(region_view_);
@@ -208,6 +231,8 @@ void VerticalTabStripWidgetDelegateView::UpdateWidgetBounds() {
     return;
   }
 
+  DCHECK(tabs::utils::ShouldShowVerticalTabs(browser_view_->browser()));
+
   auto insets = host_->GetInsets();
   widget_bounds.set_width(widget_bounds.width() + insets.width());
   if (GetInsets() != insets) {
@@ -232,7 +257,7 @@ void VerticalTabStripWidgetDelegateView::UpdateWidgetBounds() {
 
 void VerticalTabStripWidgetDelegateView::OnWidgetDestroying(
     views::Widget* widget) {
-  widget_observation_.Reset();
+  widget_observation_.RemoveObservation(widget);
 }
 
 #if BUILDFLAG(IS_MAC)
diff --git a/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.h b/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.h
index fbf7bad5687c..7784c04fd03e 100644
--- a/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.h
+++ b/browser/ui/views/frame/vertical_tab_strip_widget_delegate_view.h
@@ -8,6 +8,7 @@
 
 #include <memory>
 
+#include "base/scoped_multi_source_observation.h"
 #include "ui/views/view_observer.h"
 #include "ui/views/widget/widget_delegate.h"
 #include "ui/views/widget/widget_observer.h"
@@ -47,6 +48,7 @@ class VerticalTabStripWidgetDelegateView : public views::WidgetDelegateView,
   }
 
   // views::WidgetDelegateView:
+  void AddedToWidget() override;
   void ChildPreferredSizeChanged(views::View* child) override;
 
   // views::ViewObserver:
@@ -56,6 +58,7 @@ class VerticalTabStripWidgetDelegateView : public views::WidgetDelegateView,
   void OnViewIsDeleting(views::View* observed_view) override;
 
   // views::WidgetObserver:
+  void OnWidgetVisibilityChanged(views::Widget* widget, bool visible) override;
   void OnWidgetBoundsChanged(views::Widget* widget,
                              const gfx::Rect& new_bounds) override;
   void OnWidgetDestroying(views::Widget* widget) override;
@@ -76,7 +79,7 @@ class VerticalTabStripWidgetDelegateView : public views::WidgetDelegateView,
   base::ScopedObservation<views::View, views::ViewObserver>
       host_view_observation_{this};
 
-  base::ScopedObservation<views::Widget, views::WidgetObserver>
+  base::ScopedMultiSourceObservation<views::Widget, views::WidgetObserver>
       widget_observation_{this};
 };