McLellan began training in karate at the age of nine and also played rugby union. At the age of 19, McClellan was playing flanker for the Crusaders Rugby Club in Durban when he was offered a contract to compete for the Natal Sharks. However his passion took him into the world of mixed martial arts. McLellan compiled an amateur record of 10-0 before making his professional debut in 2009, competing exclusively for regional promotions in his native South Africa, and was a two-time EFC AFRICA champion. He compiled a professional record of 12-2, before signing with the UFC in December 2014.
