The Secret Army (French: Armée Secrète or AS, Dutch: Geheim Leger, GL) was an organisation within the Belgian Resistance, active during the German occupation of Belgium during World War II.

[1] Founded in August 1940 as the Belgian Legion, the Secret Army changed its name on a number of occasions during its existence, adopting its final appellation in June 1944.

They strongly identified with King Leopold III, expressing hostility towards Belgian politicians and communists as well as the German occupiers.

[3][4] The group's leaders attempted to forge contacts with the Belgian government in London and with the British Special Operations Executive (SOE) and MI9.

[8][9] As part of its attempt to resemble an official army, the group adopted its own uniform in April 1944, modelled on worker's overalls.

[11] Together with other groups including the Front de l'Indépendance and the Witte Brigade, Secret Army personnel played an important role in the capture of the Port of Antwerp in September 1944 before the arrival of Canadian troops, preventing the Germans from destroying the installation as they prepared to retreat.