Tomlinson returned to fall camp in 2015, competing for the starting defensive end position with A'Shawn Robinson, Jarran Reed, Jonathan Allen, and Da'Shawn Hand. He was named the backup right defensive end behind Jarran Reed to begin his third season. In Alabama's season-opener against Wisconsin, Tomlinson made two solo tackles and a career-high three pass deflections during Alabama's 35-17 victory. On September 26, 2015, Tomlinson recorded a season-high five combined tackles in a 35-0 defeat over Louisiana-Monroe. During a Week 8 contest against LSU, he collected four combined tackles and was credited for half a sack on Brandon Harris in a 30-16 victory. Tomlinson completed the 2015 season with 34 combined tackles (22 solo), a half a sack, and led the Crimson Tide with five pass deflections in 14 games. He was a part of a highly touted defensive front in 2015, that consisted of four future NFL players that would all be taken in the first two rounds of the 2016 an 2017 NFL Draft. Along with himself and nose tackle Daron Payne, the defensive line included A'Shawn Robinson (46th overall, 2016), Jarran Reed (49th overall, 2016), and Jonathan Allen (17th overall, 2017).