The 2018–19 St. Bonaventure Bonnies men's basketball team represented St. Bonaventure University during the 2018–19 NCAA Division I men's basketball season. The Bonnies, led by 12th-year head coach Mark Schmidt, played their home games at the Reilly Center in Olean, New York as members of the Atlantic 10 Conference. They finished the season 18-16, 12-6 in A-10 play for 4th place. They defeated George Mason and Rhode Island to advance to the championship game where they lost to Saint Louis.