Rotates a WPF DataGrid at design-time and run-time, including row-headers and row-details, using only XAML.

Also clears up text "smudging" that usually happens with rotating text.

Image of Rotated WPF DataGrid

How to Rotate a WPF DataGrid

Add the following sections to your DataGrid:

<DataGrid.Resources>
    <Style x:Key="DataGridBase" TargetType="Control">
        <Setter Property="LayoutTransform">
            <Setter.Value>
                <TransformGroup>
                    <RotateTransform Angle="-90" />
                    <ScaleTransform ScaleX="1" ScaleY="-1" />
                </TransformGroup>
            </Setter.Value>
        </Setter> 
        <Setter Property="TextOptions.TextFormattingMode" Value="Display" />
    </Style >
    <Style TargetType="DataGridCell" BasedOn="{StaticResource DataGridBase}"/>
    <Style TargetType="DataGridColumnHeader" BasedOn="{StaticResource DataGridBase}"/>
    <Style TargetType="DataGridRowHeader" BasedOn="{StaticResource DataGridBase}"/>
</DataGrid.Resources>             
           
<DataGrid.LayoutTransform>
    <TransformGroup>
        <RotateTransform Angle="90" />
        <MatrixTransform Matrix="-1, 0, 0, 1, 0, 0" />
    </TransformGroup>
</DataGrid.LayoutTransform>

To rotate Row Details, apply the same LayoutTransform as the DataGrid:

<DataGrid.RowDetailsTemplate>
    <DataTemplate>
        <StackPanel>
            <StackPanel.LayoutTransform>
                <TransformGroup>
                    <RotateTransform Angle="90" />
                    <MatrixTransform Matrix="-1, 0, 0, 1, 0, 0" />
                </TransformGroup>
            </StackPanel.LayoutTransform>
            <TextBlock Height="100" Text="Binding Image" />
        </StackPanel>
    </DataTemplate>
</DataGrid.RowDetailsTemplate>

Note: Some CellStyle choices will prevent the DataGrid from rotating completely, so if your DataGrid does not display as illustrated above, please remove the misbehaving CellStyle settings.