The 1991 Australian Men's Hardcourt Championships was a men's tennis tournament played on indoor hard courts in Adelaide, Australia and was part of the ATP World Series of the 1991 ATP Tour. It was the 14th edition of the tournament and was held from 31 December 1990 to 7 January 1991.
Nicklas Kulti won his only title of the year, and the 1st of his career.
Nicklas Kulti defeated Michael Stich 6–3, 1–6, 6–2
Wayne Ferreira / Stefan Kruger defeated Paul Haarhuis / Mark Koevermans 6–4, 4–6, 6–4
- ^ Total financial commitment for the tournament: $175,000.