Dit Clapper (February 9, 1907 in Newmarket, Ontario - January 21, 1978 in Newmarket, Ontario, Canada) was a Canadian Hall of Fame ice hockey player.
Clapper was given the nickname "Dit" at an early age. As a member of the Boston Bruins, he became the first player to play in the National Hockey League for twenty seasons. He was a great player both as a forward and defenseman, being named to All-Star squads at both right wing and on defense.
A lifelong member of the Bruins, in 1947 the team retired his number 5 sweater and the hall of fame selection committee waived the customary three-year waiting period, and immediately inducted him into the Hockey Hall of Fame upon the night of his retirement. His game used jersey from that night was donated to the International Hockey Hall of Fame from Clapper himself during an on-ice presentation that night announcing his retirement and induction in to the hall. The jersey is currently on display in the International Hockey Hall of Fame's museum located in Kingston, Ontario. Until he was named as coach, he had served as team captain for longer than any NHL player would until Ray Bourque and Steve Yzerman.
Clapper coached the Bruins for two seasons as a player-coach and for two more seasons after his retirement. He became the first player in NHL history to play for 20 seasons, and the last active player that played during the 1920s.
He is mentioned in the hockey cult movie Slap Shot with Toe Blake as prime examples of old time hockey - the way hockey is supposed to be played.