The 2021 GB3 Championship, known as the 2021 BRDC British Formula 3 Championship until August 2021, was a motor racing championship for open wheel, formula racing cars held across England. The 2021 season was the sixth organised by the British Racing Drivers' Club in the United Kingdom. The championship featured a mix of professional motor racing teams and privately funded drivers, and also featured the 2-litre 230-bhp Tatuus-Cosworth single seat race car in the main series. The season ran over eight triple- and quadruple-header rounds, it started on 22 May at Brands Hatch and ended on 17 October at Donington Park.[1] The series was rebranded mid-season from BRDC British Formula 3 Championship.[2]
Zak O'Sullivan took the drivers' championship at the final round at Donington Park, as Carlin took the inaugural teams' championship.