Founded in 1943, the club managed to reach the Belgian Promotion in 1976 with coach Etienne Borre, after many years in the lower Belgian Provincial leagues.

Until the end of the century, Diegem played at the fourth level, with only two seasons back in the first division of Brabant provincial league.

In 1993 the club, after 50 years of existence, received the royal prefix Koninklijke and added it to its name.

At the end of season 2002–03, Diegem finally reached the third division, where they still play.

This article about a Belgian association football club is a stub.