In Greek mythology, Actis (Ancient Greek: Ἀκτίς) was one of the Heliadae, a son of Rhodos and Helios. Actis, along with his brothers, Triopas, Macar, and Candalus, were jealous of a fifth brother, Tenages's, skill at science. They killed him and Actis escaped to Egypt.^[1] According to Diodorus Siculus, Actis built the city of Heliopolis in Egypt to honour his father Helios, and it was from Actis that the Egyptians learned astrology.^[2]