Lembit Oll (23 April 1966 – Tallinn, 17 May 1999) was an Estonian chess grandmaster. He was already successful as a junior, becoming champion of Estonia in 1982 and junior champion of the Soviet Union in 1984. He also won multiple European and World junior championships. The FIDE awarded him the IM-title in 1983 and the GM-title in 1992. From that moment, he regularly played for Estonia during Chess Olympiads and European teamchampionships. Early 1998 he reached his highest rating on the FIDE rating list: 2655.