Cox, a 6-foot-4, 231-pound senior, is the No. 4 inside linebacker available in April's NFL draft, according to ESPN's Mel Kiper Jr. Cox was named a finalist for the Butkus Award, given to the top linebacker in the FBS, and was invited to play in the upcoming Senior Bowl.
Cox announced his decision to turn pro on social media on Sunday.
In his only season at LSU, Cox was the team's third leading tackler with 58 stops, to go along with 6½ tackles for loss, one sack, three interceptions and one fumble recovery in 10 games. Kiper Jr. ranks the Kansas City native behind Penn State's Micah Parsons, North Carolina's Chazz Surratt and Missouri's Nick Bolton among inside linebacker prospects.
At North Dakota State, Cox helped the Bison win three consecutive FCS national championships from 2017-19. The Bison were 45-1 during his three seasons, in which he had 258 tackles, 32 tackles for loss and 14 sacks.