No. Steve Young's parents were not polygamists. They were members of the Church of Jesus Christ of Latter-day Saints (the "Mormon" church), which has excommunicated any members practicing polygamy since 1890.
Steve Young's great great great grandparents were polygamists.
Steve Young
Steve Young was a popular American football player. He played professional football for the NFL. He was a quarterback for 14 seasons. Steve Young also graduated from Brigham Young University.
Steve Young, former NFL Quarterback, descends from Brigham Young's seventh wife, Emily Dow Partridge. He also descends from Brigham Young's older brother Joseph Young and his first wife, Jane Bicknell.
NFL player Steve Smith played for Utah.
NFL player Steve Beauharnais played for Rutgers.
NFL player Steve Hull played for Illinois.
NFL player Steve Weatherford played for Illinois.
NFL player Steve Williams played for California.
NFL player Steve Johnson played for Kentucky.
NFL player Steve McLendon weighs 320 pounds.
NFL player Steve Beauharnais weighs 240 pounds.
NFL player Steve Hull weighs 200 pounds.