public class TestTooltipInside : ContentControl

{

public TestTooltipInside()

{

this.Loaded += this.OnLoaded;

}

    protected void OnLoaded(object sender, RoutedEventArgs routedEventArgs)
    {
        var tooltip = VisualTreeHelper.GetParent(this) as ToolTip;
        // this throws exception - cannot get the tooltip parent
        var tooltipParent = VisualTreeHelper.GetParent(tooltip);
    }
}

<Style TargetType="ToolTip">

<Setter Property="OverridesDefaultStyle" Value="true" />

<Setter Property="Placement" Value="Absolute" />

<Setter Property="Template">

<Setter.Value>

<ControlTemplate TargetType="ToolTip">

<styles:TestTooltipInside>

<Border Name="Border"

BorderThickness="1"

Width="{TemplateBinding Width}"

Height="{TemplateBinding Height}"

Background="Red"

BorderBrush="Blue">

<ContentPresenter Margin="4"

HorizontalAlignment="Left"

VerticalAlignment="Top" />

</Border>

</styles:TestTooltipInside>

</ControlTemplate>

</Setter.Value>

</Setter>

</Style>