The 2021 Castrol Toyota Racing Series was the seventeenth running of the Toyota Racing Series, the premier open-wheel motorsport category held in New Zealand. The series consisted of nine races at three meetings. It began on 24 January at Hampton Downs, in Waikato, and concluded on 14 February at Manfeild, Feilding. The season opener also hosted the 66th running of the New Zealand Grand Prix. The 2021 Toyota Racing Series was the first season in which no individual race teams were running and all drivers were under a Toyota Racing banner. This was due to the COVID situation.