After finishing in the bottom two places in the 1937–38 season, requiring them to apply for re-election to the League,[1][2] Gillingham were voted out of the competition.

[5] In August, Gillingham appointed former Everton and Tranmere Rovers player Archie Clark as player-manager, replacing Bill Harvey in the managerial role.

The following day, Britain entered the Second World War and the Southern League season was quickly abandoned.

Gillingham joined the Kent Regional League (Eastern Group) with other teams from the eastern part of the county of Kent; Tunbridge Wells Rangers were the only other Southern League team to join, but they subsequently withdrew.

The other clubs had all begun the season in the lower-level Kent League with the exception of Shorts Sports, who were a works team from Rochester.