George Plantagenet, Duke of Clarence (21 October 1449 – 18 February 1478), was the 6th son of Richard Plantagenet, 3rd Duke of York, and Cecily Neville, and the brother of English kings Edward IV and Richard III. He played an important role in the dynastic struggle between rival factions of the Plantagenets now known as the Wars of the Roses.

Though a member of the House of York, he switched sides to support the Lancastrians, before reverting to the Yorkists. He was later convicted of treason against his brother, Edward IV, and was executed. He appears as a character in William Shakespeare's plays Henry VI, Part 3 and Richard III, in which his death is attributed to the machinations of Richard.