Sullivan attended St. Thomas More High School in Rapid City, South Dakota, where he played quarterback for the football team.
[1] Sullivan joined the South Dakota Mines Hardrockers program in NCAA Division II, where he became the starting quarterback.
[2] In his four years at SDSM&T he set 17 new school records, 2 All-RMCS best quarterback and Don Hansen All-American Team.
[1] In the inaugural 2021 European League of Football season Sullivan was signed by the Frankfurt Galaxy and head coach Thomas Kösling.
[9] In the Divisional Championship playoff-game against the Cologne Centurions he scored five passing touchdowns with four different target and was nominated MVP of this game.