Leif Olve Dolonen Larsen (born April 3, 1975) is a Norwegian athlete who has competed in shot put, American football and professional boxing.

In shot putting, Larsen finished thirteenth at the 1992 World Junior Championships and fourth at the 1994 World Junior Championships. His last international athletics competition was the 1997 European under-23 Championships, where he finished eighth.^[1] His personal best throw was 18.76 metres, achieved in April 1997 in Baton Rouge.^[2]

Larsen played college football for UTEP Miners and was drafted 194th overall by the Buffalo Bills in the 2000 NFL Draft, therefore being one of the 198 players drafted before Tom Brady.^[4] Larsen appeared with the Bills in the 2000 and 2001 seasons. At the 2000 NFL Combine, Larsen bench pressed 225 lb (102 kg) 45 times, one of the best marks of all time.^[5]

Larsen retired from football to pursue a boxing career. Since his first fight in 2003, he has won nine out of nine matches, eight of these by knockout.

He defeated British heavyweight boxer Danny Williams in Pabellon Municipal, Silla, Valencia, Comunidad Valenciana, Spain on 2 December 2011.