The 1985 South African Open (also known as the 1985 Altech South African Open for sponsorship reasons) was a men's tennis tournament played on outdoor hard courts in Johannesburg, [South Africa that was part of the 1985 Nabisco Grand Prix.

It was the 82nd edition of the tournament and was held from 7 through 13 October 1985.

Unseeded Matt Anger won the singles title.

Matt Anger defeated Brad Gilbert 6–4, 3–6, 6–3, 6–2 Colin Dowdeswell / Christo van Rensburg defeated Amos Mansdorf / Shahar Perkiss 3–6, 7–6, 6–4