Reuben C. Fine (October 11, 1914 – March 26, 1993) was an American chess player, psychologist, university professor, and author of many books on both chess and psychology. He was one of the strongest chess players in the world from the mid-1930s until his retirement from chess in 1951. He was granted the title of International Grandmaster by FIDE in 1950, when titles were introduced.