2021–22 Spartan South Midlands Football League

The 2021–22 season was the 25th in the history of the 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 One at Step 6 of the English football league system.

The league constitution for this season was based on allocations for Steps 5 and 6 that were announced by The Football Association on 18 May 2021, and were subject to appeal.

After the abandonment of the 2019–20 and 2020–21 seasons due to the COVID-19 pandemic in England, numerous promotions were decided on a points per game basis over the previous two seasons.

Premier Division
The Premier Division featured 13 clubs which competed in the division last season, along with seven new clubs.
 * Transferred from the Hellenic League:
 * Ardley United
 * Flackwell Heath
 * Holmer Green
 * Risborough Rangers
 * PLus:
 * Hadley, transferred from the Essex Senior League
 * Milton Keynes Irish, promoted from Division One
 * New Salamis, promoted from Division One

Cockfosters, initially allocated to this division from the Essex Senior League, successfully appealed and the transfer was rescinded.

Division One
Division One featured nine clubs which competed in the division last season, along with eleven new clubs.
 * Transferred from the United Counties League:
 * Burton Park Wanderers
 * Irchester United
 * Northampton Sileby Rangers
 * Raunds Town
 * Rushden & Higham United
 * Wellingborough Whitworth
 * Transferred from the Hellenic League:
 * Kidlington reserves
 * Long Crendon
 * Penn & Tylers Green
 * Plus:
 * Letchworth Garden City Eagles, promoted from the Hertfordshire Senior County League
 * Thame United reserves

Division Two
Division Two featured 13 clubs which competed in the division last season, along with three new club:
 * Milton Keynes College Football Academy
 * Eynesbury United, joined from the Cambridgeshire County League
 * Risborough Rangers development, transferred from the Hellenic League Division Two North

Step 5 rankings
The 10 runners-up with the most points per game (PPG) at Step 5 were automatically promoted after the 2021–22 season. The remaining six played one-off inter-step play-off matches with the six third-from-bottom clubs with the fewest PPG from the eight divisions at Step 4. The winner of each match was promoted to Step 4 for the 2022–23 season, while each loser was relegated to Step 5.

The final points-per-game ranking of the second-placed teams was as follows:

The 12 best second-from-bottom clubs on a PPG basis out of 16 that were at Step 5 were reprieved from relegation. The four worst teams were relegated.

The final points-per-game ranking of the second-from-bottom-placed teams was also as follows: