The 1981 Madrid Grand Prix was a men's tennis tournament played on outdoor clay courts that was part of the 1981 Volvo Grand Prix tennis circuit.

It was the 10th edition of the tournament and was held at the Real Sociedad Hípica Española Club de Campo in Madrid, Spain from 28 September until 4 October 1981.

First-seeded Ivan Lendl won the singles title.

[3] Ivan Lendl defeated Pablo Arraya 6–3, 6–2, 6–2 Andrés Gómez / Hans Gildemeister defeated Heinz Günthardt / Tomáš Šmíd 6–2, 3–6, 6–3