1984–85 South Midlands League
The 1984–85 South Midlands League season was 56th in the history of South Midlands League.
Premier Division
The Premier Division featured 11 clubs which competed in the division last season, along with 5 new clubs:- New Bradwell St. Peter, promoted from last season's Division One
- Brache Sparta, promoted from last season's Division One
- Knebworth, promoted from last season's Division One
- Leighton Town, promoted from last season's Division One
- Hoddesdon Town, joined from the defunct Athenian League
Division One
The Division One featured 10 clubs which competed in the division last season, along with 4 new clubs:- Walden Rangers, relegated from Premier Division
- Milton Keynes Borough, transferred from the Hellenic League Division One
- Milton Keynes United, joined from North Bucks League
- Ickleford, joined from North Herts League