Ekaterina Aleksandrovna Lagno (Russian: ????????? ????????????? ?????; born 27 December 1989) is a Russian (formerly Ukrainian) chess grandmaster.
A chess prodigy, she earned the title Woman Grandmaster (WGM) at the age of 12 years, four months and two days.
In 2007, she was awarded the grandmaster title.She is a twice European Women's Champion and won two team gold medals at the Women's Chess Olympiad, in 2006 and 2014, playing for Ukraine and Russia respectively.
She also won team gold at the Women's World Team Championship in 2013 playing for the Ukrainian team, and the Women's European Team Championship in 2013 and 2015 playing for Ukraine in the former and Russia in the latter.
Lagno was also women's world champion in rapid chess in 2014 and in blitz chess in 2010 and 2018.