Japheth Kimutai (born December 20, 1978 in Lelmokwo, Nandi District) is a Kenyan middle distance runner who specialized in 800 metres.
In 1998 he won the gold medal at the Kuala Lumpur Commonwealth Games in a time of 1:43.82. In the same year he won the African Championships 800 metres in Dakar, Senegal. He finished fourth at the 1998 IAAF World Cup
In 1999 he won gold at the All-Africa Games.
In 2000 in Sydney for the Olympic Games Japheth failed to reach the final despite running the quickest time by a Kenyan in the games.
He had started his career brightly when in 1994 he won the silver medal at the World Junior Championships and then in 1997 when still a Junior set the World junior record in the 800 metres in a time of 1:43.64 in Zürich on August 13, 1997. The world junior record was beaten by Abubaker Kaki of Sudan in 2008.