Rein Etruk (Estonian: Rein-Toomas Etruk; March 22, 1938, Tallinn - September 11, 2012, Tallinn) was an Estonian chess player who three times won the Estonian Chess Championship.
In 1954 and 1955 Rein Etruk won Estonian Junior chess championship. Rein Etruk played for Estonia in various Soviet Team Chess Championships. He won 1st place at his table in 1958 and 1967 but in 1962 he was the third. Rein Etruk won 9 medals in Estonian Chess Championship: three gold (1965, 1969, 1973), three silver (1964, 1966, 1970) and three bronze (1962, 1967, 1968). In 1974 and 1990 he won Estonian Blitz Chess Championship. In 1971 he was 6th in strong Pärnu chess tournament.
Rein Etruk is a graduate Faculty of Philology of the University of Tartu.