Steve Zetro Souza is best known as the vocalist of the thrash metal band Exodus, holding the position from 1986 until 1992, from 2002 to 2004 and again from 2014 to 2025.

Prior to Exodus, Zetro served as the vocalist of the band Legacy (27), who, after his departure, would change their name to Testament (2). Zetro remained on good terms with his ex-Testament bandmates, having suggested his replacement, Chuck Billy, to the group, appearing on their 2001 release First Strike Still Deadly to add his vocals to a couple of re-recorded Legacy tracks, and helping pen the lyrics to Testament's 2008 release, The Formation Of Damnation.

Currently, Zetro performs with Dublin Death Patrol, a thrash act that features his brother John as well as Chuck Billy and several of Chuck's brothers, along with current and former members of Machine Head (3), Vio-Lence, and Laaz Rockit. He also sings for Tenet.