Cássio Gabus Mendes (São Paulo, August 29, 1961) is a Brazilian actor. Grandson of Otávio Gabus Mendes and son of novelist Cassiano Gabus Mendes, he is the brother of fellow actor Tato Gabus Mendes and nephew of fellow actor Luis Gustavo.

Since 1991, Cássio has been married to former actress Lídia Brondi. He debuted on television in 1982, in Elas por Elas, playing Elton. He is known for Amazonia (2007), Confessions of a Brazilian Call Girl (2011) and Baptism of Blood (2006)