Kateryna Lahno (b. December 27, 1989) is a Ukrainian chess player. She earned the FIDE title of Woman Grandmaster (WGM) at the age of 12 years and 4 months, breaking Judit Polgar's record to become the youngest ever to earn this title. She also holds the International Master (IM) title. Born in Lviv, Lahno grew up in the industrial and chess-friendly town Kramatorsk. In 2005 she lives in Donetsk.
As of October 2006, she had two of three norms necessary to earn the Grandmaster title. Lahno was the fifth seed for the 64-player knockout 2004 Women's World Chess Championship. At the age of 15 she won the 2005 European Individual Women's Championship, held in June in Chişinău, Moldova. Tied with Russian IM Nadezhda Kosintseva at the end of the 12th round with 9 points each, Lahno won both games of a two-game rapid-play tie-break playoff to win the championship. On the January 2006 list, Lahno's FIDE Rating was 2500, making her number seven among female chess players.
Although Lahno, unlike Polgar, competes for women's titles, both have stated that their true goal is to be simply World Champion.
Won IV Women's 'North Urals Cup - 2006', qualifying for a men's grandmaster