The 2017–18 Cal State Fullerton Titans men's basketball team represented California State University, Fullerton during the 2017–18 NCAA Division I men's basketball season. The Titans, led by fifth-year head coach Dedrique Taylor, played their home games at the Titan Gym, in Fullerton, California, as members of the Big West Conference. They finished the season 20–12, 10–6 in Big West play to finish in fourth place. They defeated Long Beach State and UC Davis to advance to the championship game of the Big West tournament. In the championship, they defeated UC Irvine to win the tournament and receive the conference's automatic bid to the NCAA tournament. As the No. 15 seed in the East region, they lost to Purdue in the first round.