1969–70 Southern Football League

Cambridge United won the championship, winning their second Southern League title in a row and were elected to the Football League, whilst Ashford Town (Kent), Bedford Town, Cambridge City, Dartford were all promoted to the Premier Division.

Cambridge United was elected to the Football League in place of Bradford Park Avenue.

Thus, Gloucester City and Nuneaton Borough remained in the division.

Division One consisted of 22 clubs, including 18 clubs from the previous season and four new clubs, relegated from the Premier Division: At the end of the season Wisbech Town resigned from the league and switched to the Eastern Counties Football League.

Three League clubs were re-elected, and Cambridge United were elected.