"Back That Azz Up" (eited version titled "Back That Thang Up") is a 1999 hit single by Juvenile for Cash Money Records, his biggest hit from his 1998 album 400 Degreez. The song, an explicit exploration of the same themes as Sir Mix-a-Lot's "Baby Got Back" was Juvenile's biggest hit single until the release of "Slow Motion" in 2004, peaking at #18 on the Billboard Hot 100.