Alexandra Kosteniuk (born Perm, Volga, 23 April 1984) is a Russian chess Grandmaster and former Women's World Chess Champion. She lost her title in 2010.

Alexandra is married, and lives with her husband and daughter in Key Biscayne, Miami, Florida.

Kosteniuk is now ranked 31st in the current FIDE rating list for women. She is no longer playing regularly. The highest rated woman, Judit Polgar (Hungary), never plays in female events. The second highest rated woman is Humpy Koneru (India); she has never won the women's world championship.