The 2009 Letran Knights men's basketball team represented Colegio de San Juan de Letran in the 85th season of the National Collegiate Athletic Association in the Philippines. The men's basketball tournament for the school year 2009-10 began on June 27, 2009, and the host school for the season was San Beda College. The Knights finished the double round-robin eliminations at fourth place with 12 wins against 6 losses. In the Final Four, the Knights, holding a twice-to-beat disadvantage, were eliminated by the defending champions San Beda Red Lions in one game.