The 2020-21 Gran Turismo D1 Grand Prix series is the twentieth season of D1 Grand Prix series which started at Okuibuki Motorpark on 24 July 2020 and ended at Tsukuba Circuit on 31 January 2021. The season was supposed to start on 16 May, but was delayed due to the COVID-19 pandemic. Masashi Yokoi entered the season as the defending champion.