The 1977 South African Open, also known by its sponsored name SAB Open, was a combined men's and women's tennis tournament played on outdoor hard courts in Johannesburg, South Africa.

The men's tournament was part of the 1977 Colgate-Palmolive Grand Prix while the women's event was part of the 1977–1978 Colgate International Series.

It was the 74th edition of the tournament and was held from 28 November through 6 December 1977.

Guillermo Vilas and Linky Boshoff won the singles titles.

[3][4] Guillermo Vilas defeated Buster Mottram 7–6, 6–3, 6–4 Linky Boshoff defeated Brigitte Cuypers 6–1, 6–4 Bob Lutz / Stan Smith defeated Peter Fleming / Raymond Moore 6–3, 7–5, 6–7, 7–6 Ilana Kloss / Linky Boshoff defeated Brigitte Cuypers / Marise Kruger 5–7, 6–3, 6–3 Linky Boshoff / Colin Dowdeswell defeated Ilana Kloss / Sherwood Stewart 6–4, 4–6.