The 2021 Kwik Fit British Touring Car Championship (commonly abbreviated as BTCC) was a motor racing championship for production-based touring cars held across England and Scotland. The championship features a mix of professional motor racing teams and privately funded amateur drivers competing in highly modified versions of family cars which are sold to the general public and conform to the technical regulations for the championship. The 2021 season was the 64th British Touring Car Championship season and the eleventh season for cars conforming to the Next Generation Touring Car (NGTC) technical specification. Ash Sutton successfully defended his title to become the youngest ever three time BTCC Champion.

Entering/re-entering BTCC

Changed teams

Leaving BTCC

The championship calendar was announced by the championship organisers on 20 July 2020, before it was rescheduled on 14 January 2021 in order to maximise the opportunity for spectators and guests to attend, as a result of the COVID-19 pandemic.

The first two races of the season were won by Josh Cook. Defending champion Ash Sutton won the third race after a battle with Jake Hill in mixed weather conditions.

All drivers raced under British licences.