Nelius Theron is a Namibian rugby union player for the Namibian national team and for the Leopards in the Currie Cup and the Rugby Challenge. His regular position is prop.

Theron was born in Windhoek. He made his test debut for Namibia in 2017 against Uruguay and represented the Welwitschias in the South African domestic Currie Cup and Rugby Challenge in 2017 before moving to Potchefstroom to join the Leopards for 2018.