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.

5 seed in the Sun Belt tournament, they lost in the second round to South Alabama.

They defeated Texas State in the quarterfinals of the Sun Belt tournament before losing in the semifinals to UT Arlington.

As a regular season conference champion who failed to win their conference tournament, they received an automatic bid to the National Invitation Tournament where they lost in the first round to LSU.