The 1964–65 Sussex County Football League season was the 40th in the history of Sussex County Football League a football competition in England.[1] [2]
| Competition: | Sussex County Football League Division One |
| Season: | 1964–65 |
| Winners: | Lewes |
| Promoted: | Lewes |
| Relegated: | Hastings Rangers Newhaven |
| Matches: | 272 |
| Total Goals: | 1158 |
| Prevseason: | 1963–64 |
| Nextseason: | 1965–66 |
Division One featured 15 clubs which competed in the division last season, along with two new clubs, promoted from Division Two:
| Competition: | Sussex County Football League Division Two |
| Season: | 1964–65 |
| Winners: | Sidley United |
| Promoted: | Sidley United Southwick |
| Matches: | 306 |
| Total Goals: | 1408 |
| Prevseason: | 1963–64 |
| Nextseason: | 1965–66 |
Division Two featured twelve clubs which competed in the division last season, along with six new clubs:
Also, Three Bridges United changed name to Three Bridges.