The Free Belgian forces (French: Forces belges libres, Dutch: Vrije Belgische Strijdkrachten) were soldiers from Belgium and its colonies who fought as part of the Allied armies during World War II, after the official Belgian surrender to Nazi Germany. It is distinct from the Belgian Resistance which existed in German-occupied Belgium.
In 1940, Belgian pre-war émigrés and former soldiers who had escaped occupied Belgium were formed into units within the British military which later fought in the European and Mediterranean Theatres. These included an infantry formation, which later became the Brigade Piron, as well as Commando and paratroop units. Belgians also served in the Royal Air Force and Royal Navy, serving in Belgian-only units as well as in majority-British units. Significant numbers of soldiers from the Belgian Congo fought on the Allied side against the Italians in East Africa. After the liberation of Belgium in September 1944, the Free Belgian forces formed the foundations of the new Belgian army.