Erdvilas (Erdywił, Ердивил, Erdiwił, Erdwil) was one of the 21 early dukes of Lithuania who signed a treaty with Galicia–Volhynia in 1219. He and Vykintas are the two dukes of Samogitia mentioned in the treaty. and defeated the Tatars on the banks of the Dnieper River. According to this account Vykintas was Erdvilas' brother and ruled Samogitia. When Vykintas died without leaving an heir, Erdvilas inherited Samogitia.
This account has no historical basis and is part of the Palemonids legend.