Leitus was the son of Alector (Alectryon) and Polybule or of Lacritus and Cleobule. He was the brother of Clonius, and probably the half-sibling of other Boeotian leaders, Arcesilaus and Prothoenor.
Leitus was one of the seven Achaean leaders (others being Teucer, Thoas, Meriones, Antilochus, Peneleos and Deipyrus) in front of whom Poseidon appeared during the Trojans' attack on the Achaean ships, urging them to fight back instead of acting like cowards. He was wounded by Hector on the hand at the wrist, but in the end, he was the only Boeotian leader to safely return home after the Trojan War. He also brought back the remains of Arcesilaus, another Boeotian chieftain, and buried them near the city of Lebadea. His own tomb was at Plataeae.