The 2002 Green Flag MSA British Touring Car Championship season was the 45th British Touring Car Championship (BTCC) season.
In its second year under new rules, the entry of the touring class swelled with 5 marques represented on the 2002 grid. Reigning champions Vauxhall again entered four Triple 8-run Vauxhall Astra Coupes. With 2001 champion Jason Plato not returning, 2001 runner-up Yvan Muller was partnered by James Thompson in the Vauxhall Motorsport entries while Thompson's place in the Egg Sport entry was taken by Matt Neal, fresh from a season in the European Touring Car Championship, alongside Production class graduate Paul O'Neill. They would be challenged by MG, who had trialled their West Surrey Racing-prepared ZS in the closing stages of 2001 and again had experienced touring car hand Anthony Reid and Warren Hughes at the wheel.
After, a year off developing a car built to the new rules, Honda returned with a pair of Arena Motorsport-prepared Honda Civic Type Rs for Guernseyman Andy Priaulx, who crossed over from Formula 3 after impressing on a one off BTCC outing for Vauxhall in 2001, with Northern Irishman Alan Morrison, the 2000 Production (then Class B) champion, alongside him. Proton completed the works team contingent, entering the BTCC for the first time with a pair of Impians for returning Scottish veteran David Leslie and Phil Bennett, who had been dropped by Vauxhall.
With Peugeot withdrawing their factory backing, Vic Lee Racing now headed the independents field with their pair of 406 Coupes, Dan Eaves remained and was joined by 1992 champion Tim Harvey, who had endured a difficult 2001 with the struggling JSM Alfa Romeo. The pair were joined later in the year by Formula Renault driver Carl Breeze in a third car. The works MG squad was supported from second meeting onwards by a WSR-run squad carrying the name of the girl band Atomic Kitten as part of a sponsorship deal. This team ran the young pairing of Colin Turkington and Production graduate Gareth Howell. Barwell Motorsport stepped up from the Production class to complete the Touring grid with a pair of ex-works Vauxhall Astra Coupes driven by New Zealand superbike racer Aaron Slight, who switched to car racing after a successful guest appearance for Peugeot in 2001, and 17-year-old rookie Tom Chilton.