Current members
Michael Sweet – lead vocals, guitar, piano (1982–1992, 1999–2001, 2003–present)Robert Sweet – drums, percussion (1982–1993, 1999–2001, 2003–present)Oz Fox – guitar, backing vocals (1983–1992, 1999–2001, 2003–present), lead vocals (1992–1993)Perry Richardson – bass guitar, backing vocals (2017–present)
Former members
Eric Johnson – bass, backing vocals (1982)Scott Lane – lead guitar, backing vocals (1983)John Voorhees – bass guitar, backing vocals (1983)Tim Gaines – bass guitar, backing vocals, keyboards (1983–1986, 1986–1993, 1999–2001, 2003–2004, 2010–2017)Matt Hurich – bass, backing vocals (1986)Tracy Ferrie – bass, backing vocals (2004–2010)
Session members
John Van Tongeren – keyboards (The Roxx Regime Demos), bass, keyboards (Soldiers Under Command, To Hell with the Devil, In God We Trust)Christopher Currell – synclavier, guitar (Soldiers Under Command)Billy Meyers – keyboards (In God We Trust)Steve Croes – synclavier (In God We Trust)Brad Cobb – bass (To Hell with the Devil, In God We Trust)John Purcell – keyboards (Against the Law)Jeff Scott Soto – background vocals (Against the Law)Randy Jackson – bass (Against the Law)Brent Jeffers – drums, keyboards (Against the Law), (1986–1990 touring)Tom Werman – percussion (Against the Law)Kenny Aronoff – drums (Murder by Pride)Charles Foley – keyboards (touring)Kenny Metcalf – keyboards (1985, 1986 touring)