Alexander Helios (Greek: Ἀλέξανδρος Ἥλιος; late 40 BC – unknown, but possibly between 29 and 25 BC) was a Ptolemaic prince and son of Pharaoh Cleopatra VII of the Ptolemaic dynasty and Roman triumvir Mark Antony. Alexander's fraternal twin sister was Cleopatra Selene II.

Mark Antony was related to Julius Caesar through his mother, Julia. Julia was a member of the Julii, specifically the Caesar gens (family). Her father was Lucius Julius Caesar, and Gaius Julius Caesar was her cousin. This relation made Antony and Caesar distant cousins.

Publius, Mark Anthony's Sister's Son.

Later that year, Antony was defeated by Octavian's forces at the Battle of Actium. Antony and Cleopatra fled to Egypt where, having again been defeated at the Battle of Alexandria, they committed suicide. With Antony dead, Octavian became the undisputed master of the Roman world.