Sebastian Bach (born Sebastian Philip Bierk, on April 3, 1968) is a Canadian (Canada) heavy metal (heavy metal music) singer, best known as ex-frontman of Skid Row (Skid Row (heavy metal band)).

Born in Freeport (Freeport, Bahamas), Bahamas, and raised in Peterborough (Peterborough, Ontario), Ontario, Canada, he attended nearby Lakefield College School. He is of Norwegian, French Canadian, and Native American descent. He currently resides in Lincroft, New Jersey, United States.

He and his wife, Maria Bierk, have three children, 2 sons, and 1 daughter. Their names are: Paris, London, and Sebastiana. His daughter, Sebastiana, was born in 2007. His son Paris was formerly the drummer of Thrash Metal band Severed Hand, who opened up for him on occasion and were also featured on the VH1 special I Married Sebastian Bach. Bachs father was the visual artist David Bierk. He is the brother of retired NHL goaltender Zac Bierk, model/actress Heather Dylan Bierk and Toronto based artists Jeff, Nick Alex and Charles Bierk.