The 2013 International V8 Supercars Championship was a Fédération Internationale de l'Automobile-sanctioned international motor racing series for V8 Supercars that was based in Australia. It was the fifteenth running of the V8 Supercar Championship Series and the seventeenth series in which V8 Supercars contested the premier Australian touring car title. The championship was contested over thirty-six races, starting with the Clipsal 500 Adelaide on 2 March 2013, and finishing with the Sydney Telstra 500 V8 Supercars on 8 December. The series' calendar also expanded, travelling to the United States for the first time for a race at the Circuit of the Americas in Austin, Texas.

The Supercars Championship currently known as the Repco Supercars Championship under sponsorship, is a touring car racing category in Australia and New Zealand, running as an International Series under Fédération Internationale de l'Automobile (FIA) regulations, governing the sport.