Sebastian Philip Bierk, known professionally as Sebastian Bach, is a Canadian singer and actor who achieved mainstream success as the frontman of the hard rock band Skid Row from 1987 to 1996. He has acted on Broadway and has made appearances in film and television such as Trailer Park Boys, The Masked Singer and Gilmore Girls. He continues his music career as a solo artist and since 2026, as the lead singer of Twisted Sister.