In Greek and Roman mythology, Ascanius was a son of Aeneas and Creusa. After the Trojan War, Aeneas escaped to Latium in Italy with his father and fought in the Italian Wars. Virgil's Aeneid says he had a role in the founding of Rome as the first king of Alba Longa.

He was also called Iulus or Julus. From this name comes the Gens Julia, the Julian family to which Julius Caesar belonged.