Try something like this:
<ListBox ScrollViewer.HorizontalScrollBarVisibility="Disabled" ItemsSource="{Binding YourSource}">
<ListBox.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True" />
</ItemsPanelTemplate>
</ListBox.ItemsPanel>
...
</ListBox>
If you don't need the selection stuff, you can try something with ItemsControl.
<ItemsControl ItemsControlScrollViewer.HorizontalScrollBarVisibility="Disabled" ItemsSource="{Binding YourSource}">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<WrapPanel IsItemsHost="True" />
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
...
</ItemsControl>