The 2021 South Australian National Football League season (officially the SANFL Statewide Super League) was the 142nd season of the South Australian National Football League (SANFL), the highest-level Australian rules football competition in South Australia. The season commenced on 1 April and concluded with the Grand Final on 3 October. It was contested by 10 clubs, an increase of two on the previous season, due to the return of the Adelaide and Port Adelaide reserves teams.