The 1991 Drink Drive Sandown 500 was an endurance race for Group 3A Touring Cars. The event was held on 8 September 1991 at the Sandown circuit in Victoria, Australia over 161 laps of the 3.10 km "long" circuit, totalling 499 km. The race was the first round of both the 1991 Australian Endurance Championship and the 1991 Australian Manufacturers' Championship.

The Sandown 500 is an annual endurance motor race which is staged at the Sandown Raceway, near Melbourne, Victoria, Australia from 1964. The event's name, distance – and the category of cars competing in it – has varied widely throughout its history. Most recently, the event was held as a championship event for Supercars from 2003 to 2007 and from 2012 to 2019.