Add StackPanel to Row 0
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="StackPanel" Height="300" Width="300"> <Grid Background="AliceBlue"> <Grid.RowDefinitions> <RowDefinition /> <RowDefinition /> </Grid.RowDefinitions> <StackPanel Grid.Row="0"> <Button>Button1</Button> <Button>Button2</Button> <Button>Button3</Button> </StackPanel> <StackPanel Grid.Row="1" Orientation="Horizontal"> <Button>Button1</Button> <Button>Button2</Button> <Button>Button3</Button> </StackPanel> </Grid> </Window>