The 2020–21 Southern Football League season was the 118th in the history of the Southern League since its establishment in 1894. The league has two Premier divisions (Central and South) at Step 3 of the National League System (NLS) and two Division One divisions (Central and South) at Step 4. These correspond to levels 7 and 8 of the English football league system. The allocations for Steps 3 and 4 for season 2020–21 were announced by the FA on 21 July 2020.