The 2018–19 Louisiana Ragin' Cajuns men's basketball team represented the University of Louisiana at Lafayette during the 2018–19 NCAA Division I men's basketball season. The Ragin' Cajuns were led by ninth-year head coach Bob Marlin and played their home games at the Cajundome as members of the Sun Belt Conference. They finished the season 19–13 overall, 10–8 in Sun Belt play to finish in fifth place. As the No. 5 seed in the Sun Belt tournament, they lost in the second round to South Alabama.