Helgard Lourens Müller (1 June 1963, Bloemfontein) is a South African former rugby union footballer.
Müller appeared as a replacement for the Springboks against the New Zealand Cavaliers in 1986, and against the World Invitation Team in 1989.
Müller's Springbok appearances were limited by the strong competition at centre at the time, including Danie Gerber, Michael du Plessis and Faffa Knoetze.
Müller appeared 142 times for the Free State in Currie Cup rugby, and 245 times in total, including at junior level, tour matches, the Vodacom Cup and Super Rugby.
In 1984, Müller was nominated as Young Player of the Year, together with Paul Botes, Niel Burger, Wessel Lightfoot and Uli Schmidt.