John Joseph Blum (born September 8, 1958, in Detroit, Michigan) is a retired American ice hockey defenseman. He played hockey at the University of Michigan from 1977 to 1981. He was not drafted by any NHL team. Signed as a free agent by the Edmonton Oilers in 1981, Blum played mostly in the minors before being traded to the Boston Bruins, a team that he would play for three different times during his career. He also played for the Washington Capitals and Detroit Red Wings. His best years were with the Bruins in 1984-85 and 1985-86 when he was an NHL regular.