The 2013 Avon Tyres British GT season was the 21st season of the British GT Championship. The season began on 30 March at Oulton Park and finished on 6 October at Donington Park, after ten rounds held over seven meetings.[1] Beechdean Motorsport team principal Andrew Howard won the GT3 category in an Aston Martin V12 Vantage GT3, Optimum Motorsport's Ryan Ratcliffe and Rick Parfitt Jr. won the GT4 championship, driving a Ginetta G50 while Paul Bailey and Andy Schulz took the GTC title in a Ferrari 458 Challenge, driving for Horsepower Racing.
The SRO released the entry list on 7 March at the season launch, containing 27 GT3 and 6 GT4 full season entries.
The 2013 calendar was announced on 13 September 2012.[1] A revised calendar was released on 6 December 2012, with Zandvoort replacing the Nürburgring.[39] All races except Dutch round at Zandvoort, were held in the United Kingdom.