The Deuxième Bureau de l'État-major général ("Second Bureau of the General Staff") was France's external military intelligence agency from 1871 to 1940. It was dissolved together with the Third Republic upon the armistice with Germany. However the term "Deuxième Bureau" (French: [døzjɛm byʁo]), like "MI6" and "KGB", outlived the original organization as a general label for the country's intelligence service.

French military intelligence was composed of two separate bureaus prior to World War II. The Premier Bureau was charged with informing the high command about the state of French, allied and friendly troops, while the Deuxième Bureau developed intelligence concerning enemy troops. The Deuxième Bureau was celebrated for its cryptanalytical work, but it was criticized for its involvement in the Dreyfus affair and its consistent overestimation of German military formations prior to World War II.

Its final director was Colonel Louis Rivet.