Villains who are biologically related to the hero

This is a list of villains who are relatives of one of the main protagonists, be it parent, sibling or child.

This is a common trend in fiction in an attempt to add drama and, to a lesser extent, irony to the story. Indeed, having to fight a close relative is a source of much inner turmoil to the hero, who cannot reconcile their quest and their familial ties. Often, this results in the villain attempting to turn the hero over to their side. Other times, the opposite will occur and the hero will attempt to turn the villain back to their side. The perfect example of this is, of course, Darth Vader.