2021 Supercars Championship

Shane van Gisbergen and Triple Eight Race Engineering won the drivers' and teams' championship respectively with one round to go.

It was originally planned that he would return to drive with the team as an endurance co-driver, however this did not eventuate due to ongoing COVID-19 travel restrictions.

David Reynolds and Anton de Pasquale left the team, and were replaced by Super2 drivers Will Brown and Brodie Kostecki.

[57] As a result of Team Sydney signing Fabian Coulthard and Garry Jacobson, Chris Pither and Alex Davison did not return as full-time drivers.

Pither joined Brad Jones Racing as an endurance co-driver with Macauley Jones and Davison joined Dick Johnson Racing as an endurance co-driver for brother Will Davison due to Scott McLaughlin's inability to return for Bathurst.

[54] On 4 November, Kelly Grove Racing driver David Reynolds was ruled out of the remaining Sydney Motorsport Park rounds for failing to comply with New South Wales Health Orders regarding mandatory COVID-19 vaccination.

[59] The Adelaide 500 did not appear on the calendar for the first time since 1998, with the South Australian Tourism Commission withdrawing its financial support citing the after-effects of the COVID-19 pandemic and dwindling attendances as key factors.

Sandown was dropped from the original calendar, however was reinstated after the Melbourne 400 supporting the Australian Grand Prix was postponed and later cancelled.

[75] The calendar was revised once again, as the COVID-19 Delta outbreaks in New South Wales and Victoria caused the Phillip Island, Winton and Gold Coast events to be cancelled.

[76][77][78] The series resumed at Sydney Motorsport Park, with a quadruple-header utilising various formats and a mix of day and night racing, and ended at the Bathurst 1000.

[82] Repco, who were already the Supercars’ official automotive parts retailer, succeeded Virgin Australia as the title sponsor of the series until 2025.