Shannon, who went 28-22 in four seasons at Miami, also spent 2015 to 2017 at Florida, serving as defensive coordinator and four games as interim head coach in 2017.
"Randy Shannon is a tremendous addition to our staff," Seminoles head coach Mike Norvell said in a statement. "I have all the respect in the world for the person and coach Randy Shannon is. His unique perspective will be valuable to [defensive coordinator Adam] Fuller and the rest of our defensive staff, while his relationships in Miami and throughout the state of Florida will be a great benefit for our entire program."
A Miami native who played linebacker for the Hurricanes and then the Dallas Cowboys under Jimmy Johnson, Shannon entered coaching at his alma mater in 1991. He moved to the Miami Dolphins in 1998 before returning to the University of Miami in 2001 as defensive coordinator, winning the Broyles Award as the nation's top assistant that year.
Shannon spent the next five seasons leading Miami's defense before being promoted to head coach in 2007. Other than 2012 to 2014, when he spent a season at TCU and two seasons at Arkansas, he has spent his entire coaching career in the state of Florida. He has coached nine first-team All-Americans, 78 all-conference performers and 52 players selected in the NFL draft, including 19 first-round picks.