Rightful Heir is the 149th episode of the American science fiction television series Star Trek: The Next Generation, and the 23rd episode of the sixth season.

Set in the 24th century, the series follows the adventures of the Starfleet crew of the Federation starship Enterprise-D. In this episode, Lieutenant Worf suffers a crisis of faith which leads him to an encounter with the seemingly resurrected messiah of ancient Klingon religious and historical beliefs, Kahless. He soon finds himself caught between supporting the religious figure and the more secular leader of the conventional Klingon political power structure.

This episode aired in broadcast syndication the week of May 15, 1993.