diff --git a/src/cascadia/TerminalApp/TerminalPage.cpp b/src/cascadia/TerminalApp/TerminalPage.cpp
index 3d208c749..98d28d6b2 100644
--- a/src/cascadia/TerminalApp/TerminalPage.cpp
+++ b/src/cascadia/TerminalApp/TerminalPage.cpp
@@ -854,6 +854,37 @@ namespace winrt::TerminalApp::implementation
         {
             _lastTabClosedHandlers(*this, nullptr);
         }
+        else if (_isFullscreen)
+        {
+            // GH#5799 - If we're fullscreen, the TabView isn't visible. If it's
+            // not Visible, it's _not_ going to raise a SelectionChanged event,
+            // which is what we usually use to focus another tab. Instead, we'll
+            // have to do it manually here.
+            //
+            // We can't use
+            //   auto selectedIndex = _tabView.SelectedIndex();
+            // Because this will always return -1 in this scenario unfortunately.
+            //
+            // So, what we're going to try to do is move the focus to the tab
+            // to the left, within the bounds of how many tabs we have.
+            //
+            // EX: we have 4 tabs: [A, B, C, D]. If we close:
+            // * A (tabIndex=0): We'll want to focus tab B (now in index 0)
+            // * B (tabIndex=1): We'll want to focus tab A (now in index 0)
+            // * C (tabIndex=2): We'll want to focus tab B (now in index 1)
+            // * D (tabIndex=3): We'll want to focus tab C (now in index 2)
+            const auto newSelectedIndex = std::clamp<int32_t>(tabIndex - 1, 0, _tabs.Size());
+            // _UpdatedSelectedTab will do the work of setting up the new tab as
+            // the focused one, and unfocusing all the others.
+            _UpdatedSelectedTab(newSelectedIndex);
+
+            // Also, we need to _manually_ set the SelectedItem of the tabView
+            // here. If we don't, then the TabView will technically not have a
+            // selected item at all, which can make things like ClosePane not
+            // work correctly.
+            auto newSelectedTab{ _GetStrongTabImpl(newSelectedIndex) };
+            _tabView.SelectedItem(newSelectedTab->GetTabViewItem());
+        }
     }
 
     // Method Description: