The 1991 Australian Touring Car Championship was a CAMS sanctioned motor racing title open to Group 3A Touring Cars. The title, which was the 32nd Australian Touring Car Championship, was contested over a nine-round series which began on 24 February 1991 at Sandown Raceway and ended on 11 August at Oran Park Raceway, The series was promoted as the Shell Australian Touring Car Championship and was won by Jim Richards driving a Nissan Skyline GT-R.

The Nissan Skyline GT-R is a Japanese sports car based on the Nissan Skyline range. The first cars named "Skyline GT-R" were produced between 1969 and 1972 under the model code KPGC10, and were successful in Japanese touring car racing events. This model was followed by a brief production run of second-generation cars, under model code KPGC110, in 1973.