William Reid Mitchell (born April 23, 1977) is a former Canadian professional ice hockey defenceman. He is known primarily as a physical defensive defenceman. Mitchell played Junior A in the British Columbia Hockey League (BCHL) and Saskatchewan Junior Hockey League (SJHL) before joining the college ranks with the Clarkson Knights of ECAC Hockey in 1997. He won an ECAC championship with Clarkson in 1999, while also earning playoff MVP and ECAC First Team All-Star honours.