:1991 Australian Men's Hardcourt Championships

{{Use Australian English|date=June 2020}}

{{Use dmy dates|date=December 2023}}

{{TennisEventInfo|1991|Australian Men's Hardcourt Championships|

| date=31 December 1990 – 6 January 1991

| edition=47th

| category=World Series

| draw=32S / 16D

| prize_money=$150,000{{efn|name=financial|Total financial commitment for the tournament was $175,000.}}

| surface=Hard / indoor

| location=Adelaide, Australia

| champs={{flagicon|SWE}} Nicklas Kulti{{cite web |title=1991 Adelaide – Singles draw |url=https://www.atptour.com/en/scores/archive/adelaide/7308/1991/draws?matchtype=singles |publisher=Association of Tennis Professionals (ATP)}}

| champd={{flagicon|RSA|1928}} Wayne Ferreira / {{flagicon|RSA|1928}} Stefan Kruger{{cite web |title=1991 Adelaide – Doubles draw |url=https://www.atptour.com/en/scores/archive/adelaide/7308/1991/draws?matchtype=doubles |publisher=Association of Tennis Professionals (ATP)}}

| main_name=Australian Hard Court Championships

}}

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 until 6 January 1991. Unseeded Nicklas Kulti won the singles title.{{cite book|title=The International Tennis Federation World of Tennis 1992|year=1992|publisher=CollinsWillow|location=London|isbn=9780002184304|pages=118, 134|editor=John Barrett}}