Fossen was born on November 15, 1949 in Seattle, Washington, son of Fern and Norman Fossen. His mother was a nurse and his father served during World War II in the Signal Corps and then was a Merchant Marine stationed in Japan.[5] He attended Inglemoor High School, during which he began working as a musician in the Kenmore and Bothell area of Washington with his friend Roger Fisher. Fisher's older brother Mike was their manager and arranged for gigs and negotiated for gainful compensation.[6]
Fossen began playing bass professionally in 1965.[7] In 1967, he and schoolmate Roger Fisher started the band that would become Heart. Ann Wilson joined the group in 1971 followed by her sister Nancy two years later.[6] After completing the band's sixth album Private Audition in 1982, Fossen and Michael DeRosier left the group due to mismanagement and "creative differences".[5] Fossen was inducted into the Rock and Roll Hall of Fame on April 18, 2013, as a member of Heart.[6][8]
Fossen and his current group Heart By Heart, with former Heart drummer Michael DeRosier continue to perform the songs that made the members of Heart famous.[6][7] He has also been a member of Café Authors.[9]
^Bartholomew, Penny Nelson (15 November 2001). Today In Music: A look back at pop music, UPI ("(Nov 15) Today's birthdays include ... former Heart bassist Steve Fossen in 1949 (age 52)"