Trippie Redd is being sued for using a Three 6 Mafia sample in his Love Letter To You 4 track "Death."

But he's not being sued by Three 6 Mafia.  In fact, DJ Paul is also named in the lawsuit.

Trippie's "Death" samples the 1997 Three 6 Mafia cut "Hit a Muthaf*cka" and credits DJ Paul.

However, Reginald Boyland says DJ Paul swiped the sample from his track "Pimps In The House" and claims he won the full rights to "Hit a Muthaf*cka" in 2015.

According to TMZ, this new lawsuit from Boyland is separate from a lawsuit a group of Memphis writers and producers have just filed against Paul and Juicy J for swiping over 100 Three 6 Mafia songs.