1924–25 Southern Football League

As in the previous season, the league was split into Eastern and Western Divisions.

Southampton were declared Southern League champions after defeating Swansea 2–1 in a championship play-off.

[2] Mid Rhondda United, who finished fifth in the Western Division, were the only club to apply to join the Football League, but were unsuccessful in the vote.

[3] Seven clubs left the league at the end of the season.

Mid-Rhondda United were the only non-League club to enter the elections for a place in the Football League Third Division South.