Sumlin was 51-26 in six seasons at Texas A&M. Before coaching the Aggies, Sumlin was 36-17 in four seasons at Houston, including a 13-1 record in 2011.
Texas A&M fired Sumlin after the 2017 season, when the Aggies finished the regular season 7-5. Sumlin was replaced by former Florida State coach Jimbo Fisher.
Sumlin will replace Rich Rodriguez, who was fired earlier this month in the wake of a sexual harassment allegation the university began investigating in October and a recent notice of a hostile-workplace lawsuit to be filed against him.
A source confirmed that former Texas A&M offensive coordinator Noel Mazzone will follow Sumlin to Arizona in the same capacity.
In Mazzone's first year with the Aggies in 2016, A&M was one of a handful of FBS teams to average more than 200 rushing and passing yards per game, while gaining 467 total yards per game. Those numbers dropped in 2017, as A&M averaged just 406.8 yards per game and were held to less than 100 yards rushing five times.
Sports Illustrated first reported that Mazzone will join Sumlin at Arizona.