Assistant coach Derrick Zimmerman will take over as the team's interim head coach for the rest of the season.
"After an ongoing evaluation of our men's basketball program, it was decided a change was necessary," athletic director Bryan Maggard said in a statement.
"These decisions are never easy, and this one was not made hastily. I am extremely grateful for the leadership Bob Marlin has provided the past several years. We wish he and his family all the best moving forward."
Lousiana are currently in the midst of one of their worst years since Marlin became head coach. The team is currently 3-9, which is currently the worst record in the Sun Belt, despite their 1-0 conference record (ironically the best at the moment).
Marlin was hired in 2010 as the head coach and had solid success with the program. He leaves the team with a career 269-198 record with two NCAA tournament appearances (2014, 2023), two Sun Belt regular season titles and two Sun Belt tournament championships.
He is just the fifth coach in Sun Belt history to reach the 100-win mark. In 2017, Marlin led the team to a school-best 27 wins, which led him to eventually earn the 2018 Sun Belt Coach of the Year award.
Before spending a decade in Louisiana, Marlin spent 12 years as the coach of Sam Houston State (1999-2010) where he was named Southland Coach of the Decade.
The veteran coach will now be looking for his next head coaching role.