2. A son of Menelaus by an Aetolian slave, Pieris or Teridae. Menelaus brought about a marriage between Megapenthes and a daughter of Alector. (Hom. Od. 3.188, 4.11, 15.100; Apollod. 3.11.1.) According to a tradition current in Rhodes, Megapenthes, after the death of his father, expelled Helen from Argos, and she fled to Polyxo at Rhodes. (Paus. 3.19.2 ; comp. 2.18.5, 3.18.7.)

A third personage of this name occurs in Eustathius (Eustath. ad Hom. p. 1480).