2023–24 Spartan South Midlands Football League

The 2023–24 season was the 27th 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 constitution was announced on 15 May 2023. Starting this season, the Step 5 Premier Division in the league promotes two clubs; one as champions and one via a four-team play-off. This replaced the previous inter-step play-off system. For this season only, there would have been only one club relegated from the Step 5 division.

Premier Division
The Premier Division featured 14 clubs which competed in the division last season, along with six new clubs:
 * FC Romania, relegated from the Southern League
 * London Lions, transferred from the Combined Counties League
 * Milton Keynes Irish, transferred from the United Counties League
 * Real Bedford, promoted from Division One
 * Sawbridgeworth Town, transferred from the Essex Senior League
 * Stansted, transferred from the Essex Senior League

Division One
Division One featured twelve clubs which competed in the division last season, along with eight new clubs: Also, Buckingham Athletic merged with Division Two club Buckingham United to form the new club Buckingham.
 * Cranfield United, promoted from the Bedfordshire County League
 * Huntingdon Town, transferred from the Eastern Counties League
 * Irchester United, promoted from the Northamptonshire Combination League
 * Leighton Town development, promoted from Division Two
 * Long Buckby, relegated from the United Counties League
 * Rothwell Corinthians, relegated from the United Counties League
 * Royston Town U23, promoted from the Hertfordshire Senior County League

League table
Reserve and U23 sides are ineligible for promotion to Step 5 or higher.