Nina Koivumäki (born July 23, 1985, in Pori) is a Finnish judoka, who competed as a lightweight.

She is a member of Tampereen Judo Club in Tampere, and is coached and trained by Tapio Mantymaki.

Koivumaki qualified for the women's half-lightweight class (57 kg) at the 2008 Summer Olympics in Beijing, by placing fifth from the 2007 World Judo Championships in Rio de Janeiro, Brazil.

[2] Because her opponent advanced further into the semi-finals, Koivumaki offered another shot for the bronze medal by defeating Algeria's Lila Latrous, with a koka and a golden score, in the first repechage bout.

She finished in ninth place, after losing out the second repechage bout to Japan's Aiko Sato, who successfully scored an ippon and a yoko shiho gatame (seven mat holds), in three minutes.