The 1983 Australian Sports Car Championship was a CAMS sanctioned motor racing title for drivers of Group A Sports Cars. The championship, which was the fifteenth Australian Sports Car Championship, was contested over a five round series with two races per round.
Peter Hopwood, driving the Steve Webb owned Kaditcha Chevrolet, won the championship from the Rennmax Ford of Ray Hanger. Defending series champion Chris Clearihan finished third in his older model Kaditcha Chevrolet.
The 1983 championship saw the debut of the Bap Romano owned and driven Kaditcha K583 Cosworth, the first Australian Group A Sports Car built with a closed top and Ground effects aerodynamics (Clearihan's Kaditcha also appeared with a bolted on closed top in the early rounds of the season but the top was later removed). The K583 would prove to be the fastest car in the field in 1983, and would compete in Class B as the ex-McLaren Cosworth DFV V8 was a 3.0 litre engine. However, unreliability and a DQ for dangerous driving in Round 4 at Lakeside (Hopwood also received the same penalty at Lakeside) saw Romano only finish sixth in the championship.
After finishing the opening round at Sandown in 2nd place overall and showing that he had the speed to at least match the Kaditcha Chevrolet's of Hopwood and Clearihan, the expected challenge from former Formula 5000 star Johnnie Walker driving a 1969 model Elfin ME5 Chevrolet, ended after the car was sold to a NSW based enthusiast following the opening round. The car was parked and neither it nor Walker took any further part in the series. Another potential challenger was the Mazda 12A rotary powered Tiga SC80 of Adelaide's Richard Warland (the car was driven in later rounds by open wheel driver John Smith). The car proved quick but unfortunately poor reliability from the Barry Jones built Mazda engine, the cars unnerving habit of shedding rear wheels, plus a big crash by Smith in the final round at Winton put paid to the cars chances.