The 33-year-old Wommack will be the youngest head coach at the FBS level.
Wommack has spent the last three seasons at Indiana, serving as linebackers coach in 2018 before being promoted to defensive coordinator in 2019. Before joining Tom Allen's staff, he spent the two prior seasons as defensive coordinator at South Alabama.
Wommack's stint with the Jaguars was successful. During his first season with South Alabama, it finished 56th nationally, allowing 27 points per game. That alone doesn't seem like much, but when you consider that the same defense had finished 115th nationally while allowing 37.3 points per game, it was a significant improvement.
This year at Indiana, Wommack's defense has been one of the driving factors in the program's best season in recent history. The Hoosiers have allowed only 19.4 points per game this season, fourth in the Big Ten and 20th nationally.
"To be the head coach at the University of South Alabama is the opportunity of a lifetime! Melissa and I could not be more excited to return to a city that we love," said Wommack in a statement released by the program. "Believing in all that this community has to offer, we proudly join a team of exceptional leaders in steering the Jaguar football program to reach its greatest potential. My staff and I will lead the Jaguars with a respect that honors those who have built this program; relational coaching that transforms the lives of our student-athletes; and, a contagious intensity that ignites and expands our great fan base. Our best is yet to come, GO JAGS!"
Wommack replaces Campbell, who was let go following a 4-7 start to the season. Campbell went 9-26 in his three seasons with the Jaguars.