Del Rio broke the news that he plans to transfer through Twitter on Wednesday.
"I had an incredible year at Bama, it's sad to say that it will be my last," Del Rio said in a Twitter post. "I'm excited for the next chapter of my life and what it will bring."
Del Rio did not give any specifics on where he'll transfer.
Del Rio, son of Denver Bronco defensive coordinator Jack Del Rio, was the third-string quarterback behind backup Blake Sims and starter AJ McCarron.
Del Rio was expected to compete for the starting job this spring.
With Del Rio leaving, new offensive coordinator Lane Kiffin still has options at quarterback. Along with Sims, a senior-to-be, the Tide has Alec Morris, Cooper Bateman, Parker McLeod and David Cornwell on scholarship. Morris will be a sophomore next season, while Bateman and McLeod will be redshirt freshmen. Cornwell is an incoming freshman.