Earlier in the week, Fitzpatrick told ESPN's Trey Wingo and Mike Golic that it was "pretty clear" which way he was leaning in regards to the National Football League, implying that he would turn pro.
Fitzpatrick is seen as a near lock to go in the top 10 of April's draft.
"Having been thoroughly prepared for the next step, I am truly ready, because in the beginning, I chose the right school", Ridley said.
Fitzpatrick joins teammates Ronnie Harrison, Bo Scarbrough, Da'Ron Payne and Calvin Ridley as underclassmen to make the decision to forego their final year of eligibility to make the jump to the pros. "I feel I played well enough to go high as I wanted to".
Ridley, a projected first-round pick, announced he would forgo his senior year of college football in a tweet.
Leading rusher Damien Harris has chose to return for his senior season, according to a report from AL.com, citing unnamed sources.
Fitzpatrick is viewed by several draft experts as the top safety in the draft class, and Harrison also has been given a first-round grade.
Scarbrough was Alabama's top offensive threat during its playoff run after the 2016 season, shredding Washington for 180 yards on 19 carries in the Peach Bowl national semifinal.
The decision by Payne (6-2, 308 pounds) was reported by AL.com and ESPN. He caught the game-tying touchdown in the fourth quarter. Scarbrough rushed for 596 yards and 8 touchdowns.
He added: "I can't say enough about the contribution these guys have made". "It just seems like yesterday we were in their houses recruiting them".