A graduate of the Saint-Cyr Military Academy, he entered the army in 1856 and saw service in Italy, Algeria, Indochina, and the Franco-German War (1870–71). Wounded in suppressing the 1871 Paris Commune, he was appointed brigadier general in May 1880 and director of infantry in 1882. Two years later he was appointed to command the army in Tunisia but was recalled because of differences of opinion with Pierre-Paul Cambon, the political resident. Returning to Paris, he began to take part in politics under the aegis of Georges Clemenceau and the Radical Party. In January 1886 he entered the government of Charles-Louis de Saulces de Freycinet as minister of war.

By introducing reforms for the benefit of all ranks and by courting popularity openly, Boulanger came to be accepted by the people as the man destined to avenge France's defeat in the Franco-German War. He thus became a tool in the hands of groups hostile to the existing republican dispensation. On Freycinet's defeat in December 1886, Boulanger was retained at the ministry of war by the new prime minister, René Goblet, though Clemenceau by this time had withdrawn his patronage from the obviously too compromising general. On Goblet's retirement from office in May 1887, the Paris populace clamoured for their “brav' général,” but Maurice Rouvier, who had long been hostile to Boulanger, refused to include him in his government, and the General was sent to Clermont-Ferrand to command the XIII Corps. A Boulangist “movement,” however, was now in full swing. Many Bonapartists had attached themselves to the General, and the royalists were led to support him by the Duchesse d'Uzès (Marie Anne Clémentine de Rochechouart-Mortemart), who contributed large sums to the General's political fund.

Boulanger was deprived of his command in 1888 for coming three times to Paris without leave and in disguise and for visiting Prince Napoleon at Prangins in Switzerland. His name was removed from the army list, but almost immediately he was elected deputy for the Nord. In June 1888 his proposals for revising the constitution were rejected by the Chamber, whereupon he resigned. An altercation with Charles Floquet led to a duel (July 13) in which the elderly prime minister inflicted a severe wound on the General. Neither this humiliation nor Boulanger's failure as an orator checked his followers' enthusiasm, and throughout 1888 his personality dominated French politics.

In January 1889 Boulanger was returned as deputy for Paris by an overwhelming majority. When the election results were announced, wildly shouting masses of his supporters urged him to take over the government immediately. Boulanger declined and spent the evening with his mistress instead. His failure to seize control at the crucial moment was a severe blow to his following. A new government under Pierre Tirard, with Ernest Constans as minister of the interior, decided to prosecute Boulanger, and within two months the Chamber was requested to waive the General's parliamentary immunity. To his friends' astonishment, Boulanger fled from Paris on April 1, going first to Brussels and then to London. He was tried in absentia for treason by the Senate as high court and condemned on Aug. 14, 1889, to deportation. In the elections of 1889 and 1890 his supporters received setbacks, and public enthusiasm for his cause dwindled away. In 1891 Boulanger committed suicide in Brussels at the cemetery of Ixelles, over the grave of his mistress, Marguerite de Bonnemains, who had died two months earlier.