The No. 48 overall recruit becomes the highest-ranked prospect in the Seminoles' class.
"I loved the school, culture, environment and got the family vibe I was looking for, and I decided to make the right decision and commit," Jennings told ESPN on Friday.
Jennings is a 6-foot-3, 220-pound recruit out of Sandalwood High School in Jacksonville, Florida, and is ranked as the No. 4 outside linebacker and the No. 10 recruit in the state of Florida in 2021.
He's the son of former Florida State football player Bradley Jennings, who played for the Seminoles in the late '90s and early 2000s.
Landing Jennings early in the process is a significant win for new coach Mike Norvell and his staff. With Norvell having just a short amount of time to fill his class at Florida State after being hired in December, the 2020 class finished No. 19 overall.
Norvell will have more time to fill out the Class of 2021, establish relationships with prospects and try to bring on board elite-level recruits such as Jennings.
The talented linebacker is the first ESPN Junior 300 commit in the class for Florida State but the fifth total commit. Jennings joins running back KeyShawn Spencer, defensive end Joshua Farmer, quarterback Luke Altmyer and linebacker Dequaveon Fuller.