The 2021 British Athletics Championships was the national championships in outdoor track and field for athletes in the United Kingdom, which also served as the main qualifying event for athletics competitors for the delayed 2020 Summer Olympics.

On 29 June 2021, UK Athletics announced 65 athletes that would compete for Team GB at the Olympics, taking the total number of British athletics competitors at the Games to 72. In July 2021, four more athletes qualified for the Games based on their World Athletics rankings.