Early career 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.
Ultimate Fighting Championship McLellan made his promotional debut against
Bartosz Fabiński on 11 April 2015 at
UFC Fight Night 64. He lost the fight via unanimous decision. McLellan faced Bubba Bush on 24 October 2015 at
UFC Fight Night 76. He won the fight via TKO in the closing seconds of the third round. McLellan next faced
Magnus Cedenblad on 8 May 2016 at
UFC Fight Night 87. He lost the fight via TKO in the second round. McLellan was defeated by
Alessio Di Chirico on 27 August 2016 at
UFC on Fox 21. He lost the fight via split decision. McLellan faced promotional newcomer
Paulo Costa on 11 March 2017 at
UFC Fight Night 106. He lost the fight via TKO in the first round. ==Championships and accomplishments==