The Isthmian League is a regional football league covering Greater London, East and South East England, featuring mostly semi-professional clubs.

Civil Service Football Club is an English football club based in the city of London. The club originally played both association football and rugby football and the Civil Service, along with Blackheath F.C., is one of the two clubs that can claim to be a founder member of both The Football Association and the Rugby Football Union. However, the rugby club is now a distinct entity and appears to have been so since the late nineteenth century. They are currently members of the Southern Amateur League Senior Division 1.