"It was a tough decision like I have always said," Clark told reporters. "But I just felt down deep in my heart that this would be the school for me."
At 6-foot-3 and 218 pounds, Clark has played quarterback this year for Calera, but is projected to be a safety in college. He has led the team to a 5-0 start and the No. 1 ranking in Class 4A.
Clark is the No. 59 player in the nation for the 2014 class and a four-star recruit, according to Rivals.com. 247sports ranks Clark as the No. 109 prospect. Scout.com lists Clark as the 114th best senior this season. Clark also ranks No. 96 this year on the 2014 ESPN 300.
"This is a very firm commitment," Clark said.
Clark is the Tide's 21st commitment for its 2014 class.