Koko Tsurumi (鶴見虹子, Tsurumi Kōko^?) (born September 28, 1992) is a Japanese artistic gymnast. She is the 2009 World all-around bronze medalist and uneven bars silver medalist.

Tsurumi was a member of the 2008 Japanese Olympic Team. The women's gymnastics team placed 5th in team competition. Individually, Tsurumi placed 17th in the all-around final and 8th in the balance beam event final.

Tsurumi competed at the 2009 American Cup and placed 7th all-around.

At the 2009 World Championships in London, Koko Tsurumi competed a historic performance to win the individual all-around bronze medal. During event finals, Tsurumi won the silver medal on uneven bars and placed 6th on balance beam. Tsurumi is the first Japanese woman gymnast to win a World Championships medal in 43 years. (The previous Japanese woman gymnast to win a World medal was Keiko Ikeda at the 1966 World Championships, where she had also won uneven bars silver and all-around bronze, as well as team bronze.)

Koko competed at the 2010 Japan Cup and placed second all-around behind Ksenia Afanasyeva. At that competition, Tsurumi scored a 15.400 on uneven bars. She debuted a new bars routine with an ono turn to half turn connected to a Tkachev and an ono turn connected to a Jaegar. At the 2010 World Artistic Gymnastics Championships, Tsurumi experienced problems with consistency and failed to make any event finals and placed 21st in the All Around, behind countrywoman Rie Tanaka.