diff --git a/src/SamplesApp/SamplesApp.UITests/ScreenshotInfo.cs b/src/SamplesApp/SamplesApp.UITests/ScreenshotInfo.cs
index 009839a9cb14..5debdcdb9725 100644
--- a/src/SamplesApp/SamplesApp.UITests/ScreenshotInfo.cs
+++ b/src/SamplesApp/SamplesApp.UITests/ScreenshotInfo.cs
@@ -23,6 +23,11 @@ public ScreenshotInfo(FileInfo file, string stepName)
 		public static implicit operator ScreenshotInfo(FileInfo fi) => new ScreenshotInfo(fi, fi.Name);
 
 		public Bitmap GetBitmap() => _bitmap ??= new Bitmap(File.FullName);
+
+		public int Width => GetBitmap().Width;
+		
+		public int Height => GetBitmap().Height;
+
 		public void Dispose()
 		{
 			_bitmap?.Dispose();
diff --git a/src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Controls/FlyoutTests/UnoSamples_Tests.Flyout.cs b/src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Controls/FlyoutTests/UnoSamples_Tests.Flyout.cs
index e9821c6b3bf0..4b753f037b42 100644
--- a/src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Controls/FlyoutTests/UnoSamples_Tests.Flyout.cs
+++ b/src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Controls/FlyoutTests/UnoSamples_Tests.Flyout.cs
@@ -233,5 +233,20 @@ public void Flyout_Namescope()
 
 			_app.FastTap(closeButton);
 		}
+
+		[Test]
+		[AutoRetry]
+		public void Flyout_ShowAt_Window_Content()
+		{
+			Run("UITests.Windows_UI_Xaml_Controls.FlyoutTests.Flyout_ShowAt_Window_Content");
+
+			var windowButton = _app.Marked("WindowButton");
+
+			_app.WaitForElement(windowButton);
+			_app.FastTap(windowButton);
+
+			using var result = TakeScreenshot("Result", ignoreInSnapshotCompare: true);
+			ImageAssert.HasColorAt(result, result.Width / 2, 150, Color.Red);
+		}
 	}
 }
diff --git a/src/SamplesApp/UITests.Shared/UITests.Shared.projitems b/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
index 720969906bb1..0aaa4ca4bfa9 100644
--- a/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
+++ b/src/SamplesApp/UITests.Shared/UITests.Shared.projitems
@@ -1445,6 +1445,10 @@
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
     </Page>
+    <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Flyout\Flyout_ShowAt_Window_Content.xaml">
+      <SubType>Designer</SubType>
+      <Generator>MSBuild:Compile</Generator>
+    </Page>
     <Page Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Flyout\Flyout_TemplatedParent.xaml">
       <SubType>Designer</SubType>
       <Generator>MSBuild:Compile</Generator>
@@ -5552,6 +5556,9 @@
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Flyout\Flyout_Namescope.xaml.cs">
       <DependentUpon>Flyout_Namescope.xaml</DependentUpon>
     </Compile>
+    <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Flyout\Flyout_ShowAt_Window_Content.xaml.cs">
+      <DependentUpon>Flyout_ShowAt_Window_Content.xaml</DependentUpon>
+    </Compile>
     <Compile Include="$(MSBuildThisFileDirectory)Windows_UI_Xaml_Controls\Flyout\Flyout_TemplatedParent.xaml.cs">
       <DependentUpon>Flyout_TemplatedParent.xaml</DependentUpon>
     </Compile>
diff --git a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml
new file mode 100644
index 000000000000..052c95e6fe93
--- /dev/null
+++ b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml
@@ -0,0 +1,15 @@
+<Page
+    x:Class="UITests.Windows_UI_Xaml_Controls.FlyoutTests.Flyout_ShowAt_Window_Content"
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:UITests.Windows_UI_Xaml_Controls.Flyout"
+    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
+    mc:Ignorable="d"
+    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
+
+    <StackPanel>
+		<Button Click="ButtonButton_Click">Show at button</Button>
+		<Button Click="WindowButton_Click" x:Name="WindowButton">Show at window</Button>
+    </StackPanel>
+</Page>
diff --git a/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml.cs b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml.cs
new file mode 100644
index 000000000000..9f60c3b24371
--- /dev/null
+++ b/src/SamplesApp/UITests.Shared/Windows_UI_Xaml_Controls/Flyout/Flyout_ShowAt_Window_Content.xaml.cs
@@ -0,0 +1,49 @@
+using Uno.UI.Samples.Controls;
+using Windows.UI.Xaml;
+using Windows.UI.Xaml.Controls;
+using Windows.UI.Xaml.Media;
+
+// The Blank Page item template is documented at https://go.microsoft.com/fwlink/?LinkId=234238
+
+namespace UITests.Windows_UI_Xaml_Controls.FlyoutTests
+{
+	/// <summary>
+	/// An empty page that can be used on its own or navigated to within a Frame.
+	/// </summary>
+	[Sample]
+	public sealed partial class Flyout_ShowAt_Window_Content : Page
+	{
+		public Flyout_ShowAt_Window_Content()
+		{
+			this.InitializeComponent();
+		}
+
+		private void ButtonButton_Click(object sender, RoutedEventArgs e)
+		{
+			Windows.UI.Xaml.Controls.Flyout flyout = new Windows.UI.Xaml.Controls.Flyout();
+			flyout.Content =
+				new Border()
+				{
+					Width = 300,
+					Height = 300,
+					Background = new SolidColorBrush(Windows.UI.Colors.Red),
+				};
+
+			flyout.ShowAt((Button)sender);
+		}
+
+		private void WindowButton_Click(object sender, RoutedEventArgs e)
+		{
+			Windows.UI.Xaml.Controls.Flyout flyout = new Windows.UI.Xaml.Controls.Flyout();
+			flyout.Content =
+				new Border()
+				{
+					Width = 300,
+					Height = 300,
+					Background = new SolidColorBrush(Windows.UI.Colors.Red),
+				};
+
+			flyout.ShowAt(global::Windows.UI.Xaml.Window.Current.Content as FrameworkElement);
+		}
+	}
+}
diff --git a/src/Uno.UI/UI/Xaml/Controls/Flyout/FlyoutBase.cs b/src/Uno.UI/UI/Xaml/Controls/Flyout/FlyoutBase.cs
index a21f8e41a038..782189936ae4 100644
--- a/src/Uno.UI/UI/Xaml/Controls/Flyout/FlyoutBase.cs
+++ b/src/Uno.UI/UI/Xaml/Controls/Flyout/FlyoutBase.cs
@@ -325,7 +325,10 @@ private protected virtual void ShowAtCore(FrameworkElement placementTarget, Flyo
 						throw new ArgumentException("Invalid flyout position");
 					}
 
-					// UNO TODO: clamp position within contentRect
+					var visibleBounds = ApplicationView.GetForCurrentView().VisibleBounds;
+					positionValue = new Point(
+						positionValue.X.Clamp(visibleBounds.Left, visibleBounds.Right),
+						positionValue.Y.Clamp(visibleBounds.Top, visibleBounds.Bottom));
 
 					SetTargetPosition(positionValue);
 				}
diff --git a/src/Uno.UI/UI/Xaml/Controls/Popup/PlacementPopupPanel.cs b/src/Uno.UI/UI/Xaml/Controls/Popup/PlacementPopupPanel.cs
index 32a5e0a7b949..e6d1b1cd7f9c 100644
--- a/src/Uno.UI/UI/Xaml/Controls/Popup/PlacementPopupPanel.cs
+++ b/src/Uno.UI/UI/Xaml/Controls/Popup/PlacementPopupPanel.cs
@@ -285,6 +285,48 @@ ref controlYPos
 			{
 				this.Log().LogDebug($"Calculated placement, finalRect={finalRect}");
 			}
+
+			// Ensure the popup is not positioned fully beyond visible bounds.
+			// This can happen for example when the user is trying to show a flyout at
+			// Window.Current.Content - which will match Top position, which would be outside
+			// the visible bounds (negative Y).
+
+			if (finalRect.Bottom < visibleBounds.Top)
+			{
+				finalRect = new Rect(
+					finalRect.Left,
+					visibleBounds.Top,
+					finalRect.Width,
+					finalRect.Height);
+			}
+
+			if (finalRect.Top > visibleBounds.Bottom)
+			{
+				finalRect = new Rect(
+					finalRect.Left,
+					visibleBounds.Bottom - finalRect.Height,
+					finalRect.Width,
+					finalRect.Height);
+			}
+
+			if (finalRect.Right < visibleBounds.Left)
+			{
+				finalRect = new Rect(
+					visibleBounds.Left,
+					finalRect.Top,
+					finalRect.Width,
+					finalRect.Height);
+			}
+
+			if (finalRect.Left > visibleBounds.Right)
+			{
+				finalRect = new Rect(
+					visibleBounds.Right - finalRect.Width,
+					finalRect.Top,
+					finalRect.Width,
+					finalRect.Height);
+			}
+
 			return finalRect;
 		}
 
diff --git a/src/Uno.UI/UI/Xaml/Controls/TextBlock/TextVisual.skia.cs b/src/Uno.UI/UI/Xaml/Controls/TextBlock/TextVisual.skia.cs
index 9fc64caf0a01..916180275c00 100644
--- a/src/Uno.UI/UI/Xaml/Controls/TextBlock/TextVisual.skia.cs
+++ b/src/Uno.UI/UI/Xaml/Controls/TextBlock/TextVisual.skia.cs
@@ -139,7 +139,7 @@ public void UpdateForeground()
 
 		internal override void Render(SKSurface surface)
 		{
-			if (!string.IsNullOrEmpty(_owner.Text))
+			if (!string.IsNullOrEmpty(_owner.Text) && Size != default)
 			{
 				UpdateForeground();