Answer by Chris for Aligning controls on both left and right side in a stack panel in WPF

Even though this is old, should someone come across this like I did, here's a simple solution.

Make a new grid and inside that grid put two stack panels with different Horizontal Alignment.

<Grid><StackPanel Orientation="Horizontal" HorizontalAlignment="Left"><!--Code here--></StackPanel><StackPanel Orientation="Horizontal" HorizontalAlignment="Right"><!--Code here--></StackPanel></Grid>

The possible issue is that now without extra handling the two could overlap with each other.