The 6-foot-1, 190-pound Bonnafon, considered the No. 16 quarterback nationally in the Class of 2014 by Scout.com, picked the Cardinals over Illinois and serious interest from Ohio State and several others.
"I've been knowing this for a long time," he told Cardinal Authority. "I just wanted to get it off my chest and focus on my senior year."
Bonnafon called U of L coach Charlie Strong on Sunday afternoon, giving the coach his third commitment in three days. Four-star defensive end De'Asian Richardson committed on Friday and five-star wide receiver James Quick committed on Saturday. Bonnafon and Quick are teammates and close friends.
"That helps," Bonnafon said. "But I would have committed there even had James gone somewhere else. I'm glad he didn‘t though."
Bonnafon becomes the first commitment for U of L in the '14 class.
Bonnafon, a dual-threat quarterback, had over 40 total touchdowns on the freshman team at Trinity. He was the backup and starting JV quarterback as a sophomore. He completed 6 of 8 passes for 280 yards and one TD on the varsity level. As a junior, he played wide receiver and was the backup quarterback.
He caught 37 passes for 509 yards and six touchdowns and completed 4 of 4 passes for 42 yards and three touchdowns as a QB.
Bonnafon will be one of the state's top prospects in '14 and is ranked No. 240 nationally by Scout.com.
"I'm really excited," he said. "All of the Louisville coaches are great and I just feel at home. It was a good decision for me because it's the right place.
"Quarterback is the only position they want me to play and they have been high on me for a while. They trust my ability and that was big."
Bonnafon said Strong, "asked me what number I wanted to wear," when he arrives on campus in the fall of '14.
"I told him No. 5," Bonnafon said.
Check out the highlight video below of Bonnafon from the game against St. Xavier when he was on junior varsity as a sophomore: