In Greek mythology, Prothoenor (Ancient Greek: Προθοήνωρ) was one of the Greek leaders in the Trojan War, from Thespiae in Boeotia, son of Areilycus (Archilycus) and Theobule, brother of Arcesilaus; he commanded eight ships. In one account, Prothoenor was the son of Alector and Arteis, and thus a half-brother of Leitus and Clonius. According to the Iliad, he was killed by Polydamas, who immediately began to boast about it.