The 2018 Michelin Ginetta GT4 Supercup is a multi-event, one make GT motor racing championship held across England and Scotland. The championship features a mix of professional motor racing teams and privately funded drivers, competing in Ginetta G55s that conform to the technical regulations for the championship. It forms part of the extensive program of support categories built up around the BTCC centrepiece. It is the eighth Ginetta GT4 Supercup, having rebranded from the Ginetta G50 Cup, which ran between 2008 and 2010. The season commenced on 1 April at Brands Hatch – on the circuit's Indy configuration – and concludes on 30 September at the same venue, utilising the Grand Prix circuit, after twenty-two races held at eight meetings, all in support of the 2017 British Touring Car Championship season.