The 1972–73 Southern Football League season was the 70th in the history of the league, an English football competition.
Kettering Town won the championship, winning their third Southern League title, whilst Atherstone Town, Grantham, Maidstone United and Tonbridge were all promoted to the Premier Division.
Eight Southern League clubs applied to join the Football League at the end of the season, but none were successful.
Division One North consisted of 22 clubs, including 13 clubs from the previous season and nine new clubs: At the end of the season Lockheed Leamington was renamed AP Leamington.
Alongside the four League clubs facing re-election, a total of 10 non-League clubs applied for election, eight of which were Southern League clubs.