Alexander Vlahos is a Welsh actor, writer, and director best known for playing Philippe, Duke of Orléans, in the Canal+ television series Versailles. In 2012, Vlahos took the role of the adult Mordred, in the final series of the BBC One drama Merlin.

Monsieur Philippe I, Duke of Orléans was the younger son of King Louis XIII of France and Anne of Austria, and the younger brother of King Louis XIV. He was the founder of the House of Orléans, a cadet branch of the ruling House of Bourbon.