He was a Florida commitment before decommiting in May.
Miller stands 6-foot-4 and 215 pounds and is rated a four-star prospect by Rivals.com, Scout.com and 247sports, which lists him as the No. 3 outside linebacker recruit nationally.
“It feels really good,” Miller told 247sports. “I didn’t want to rush anything. I feel like I knew where I want to go and once I found the best place for me, to go on ahead and do it. That’s how I feel about Alabama. It does feel good to have it done so I can focus on my senior year and relax a little.”
Miller is the son of former NFL linebacker Corey Miller, who played at South Carolina. Corey Miller spent seven seasons with the New York Giants and one with the Minnesota Vikings.