The 2003–04 Southern Football League season was the 101st in the history of the league, an English football competition. It was the last season for the Southern Football League as a feeder for the Conference Premier. At the end of the season, the Premier Division was replaced as a level 6 league (along with the Northern Premier League Premier Division and Isthmian League Premier Division) by the newly formed Conference North and Conference South. The Premier Division lost more than half its clubs to newly formed divisions, and the two regional divisions had a number of their clubs promoted to the Premier Division to replace them. Thus, the Southern Football League divisions downgraded to 7-8 levels.