The Police Sports Association was founded in the mid-1940s to organise football activities for the Singapore Police Force. They sent two teams to compete in the Singapore Amateur Football Association League in the 1950s and 1960s, but neither team won any trophies. Under coach Choo Seng Quee, Police SA won the inaugural President's Cup in 1968, then reached and lost the next two finals. In 1979, they joined the National Football League, were placed in Division III and immediately earned promotion to Division II. 1980 was a watershed year for the Police SA, as they won the Division II title, the President's Cup and the Boggars Cup. In 1985, they were national league champions, after setting a national record as the only team to go unbeaten for 17 consecutive games. The convincing performances of Police SA led to their selection as one of eight teams to compete in the newly formed S.League.
The 1996 season of the S.League was split into two series. Tiger Beer Series winners Geylang United defeated Pioneer Series winners Singapore Armed Forces in the Championship playoff to clinch the S.League title.
2003 saw the introduction of penalty shoot-outs if a match ended in a draw in regular time. Winners of penalty shoot-outs gained two points instead of one.