2020–21 Spartan South Midlands Football League

The 2020–21 season was the 24th in the history of Spartan South Midlands Football League, a football competition in England. The league operates three divisions, two of which are in covered in this article, the Premier Division, at Step 5 and Division 1 at Step 6 of the English football league system.

The allocations for Steps 5 and 6 for season 2020–21 were announced by the FA on 21 July, and were subject to appeal.

The 2020–21 season started in September and was suspended in December a result of the COVID-19 pandemic in England. The league season was subsequently abandoned on 24 February 2021.

The scheduled restructure of non-League took place at the end of the season, with new divisions added to the Combined Counties and United Counties Leagues at Step 5 for 2021-22. Promotions from Steps 5 to 4 and 6 to 5 were based on points per game across all matches over the two cancelled seasons (2019–20 and 2020–21), while teams were promoted to Step 6 on the basis of a subjective application process.

Premier Division
The Premier Division comprised the same set of 21 teams which competed in the aborted competition the previous season.

Division One
Division One comprised 17 teams, two less than the previous season, after FC Broxbourne Borough resigned from the league and Brimsdown were relocated to the Eastern Counties League. Also, Hackney Wick were initially relocated from the Eastern Counties League, but this relocation was reversed.

Division Two
Division Two featured 14 clubs which competed in the division last season, along with one new club:
 * Berkhamsted Comrades