Adrian McCallum (December 17, 1982) is a British professional wrestler currently working under the name Lionheart. He made his debut in 2002 for British Championship Wrestling in Barrhead. He spent several years expanding his resume on the Scottish Wrestling scene in companies Premier British Wrestling, Insane Championship Wrestling, Scottish Wrestling Alliance and more. He made his English debut for WrestleZone Wrestling as well as his Irish debut for Irish Whip Wrestling in 2004, joining fellow BCW alumni Drew Galloway as a regular on the English companies shows. He continued his expansion within England by competing for various other promotions before landing in the now defunct One Pro Wrestling (1PW) in 2006. He would eventually become the group's last ever World heavyweight Champion i