Born and raised in Pennsylvania, Dempsey played football, and also competed in wrestling growing up as a youngster.
He fought primarily for regional promotions in Western Pennsylvania where he compiled a record of 10-1 competing in both the light heavyweight and middleweight divisions before signing with the UFC on the summer of 2014.
[3] Dempsey made his promotional debut as a short notice replacement against Ilir Latifi on July 19, 2014, at UFC Fight Night 46, filling in for Tom Lawlor.
[4] Latifi effectively used leg kicks to disable his opponent, before finishing him with punches, ending the fight by a first round knockout.
[7] Dempsey returned to the light heavyweight division as a short notice replacement to face promotional newcomer Jonathan Wilson on August 8, 2015, at UFC Fight Night 73, filling in for Jared Cannonier.