The 1981 South Australian Open was a men's Association of Tennis Professionals tennis tournament held on outdoor grass courts at Memorial Drive in Adelaide, Australia that was part of the 1981 Volvo Grand Prix circuit.

It was the 79th edition of the tournament and was held from 5 January until 11 January 1981.

Fifth-seeded Mark Edmondson won the singles title.

[3] Mark Edmondson defeated Brad Drewett 7–5, 6–2 Colin Dibley / John James defeated Craig Edwards / Eddie Edwards 6–3, 6–4