Ashton Gillotte was born in Ohio and moved to Florida when he was three years old. He attended Boca Raton Community High School, and as a senior in 2020, he was the Sun Sentinel's Palm Beach County 8A-6A defensive player of the year after recording 55 tackles and 10 sacks in seven games. Gillotte was a three-star recruit when he committed to the University of Louisville during his senior season.
As a true freshman at Louisville in 2021, Gillotte played in 12 games and had 19 tackles and four sacks. He earned All-ACC honorable mention accolades after collecting 24 tackles and was tied for third on the team with six sacks. During is junior season Gillotte played dominant football and was named first team All-ACC and second team All-American honors. He was tops on the defensive line with 45 tackles, 14.5 tackles for loss and 11 sacks.