Trained in law, Bourgeois entered the civil service in 1876 and by 1887 had advanced to the position of prefect of police for the Seine département. In 1888 he was elected to the National Assembly as a deputy from the Marne district. After serving in a number of ministerial posts, he became premier (Nov. 1, 1895–April 21, 1896). Later, he was the head of the Radical-Socialist Party. He represented the Marne (1905–23) in the Senate and was its president from 1920 to 1923.

Bourgeois was a French delegate to the Hague Conference of 1899, where he espoused international cooperation among nations. In 1903 he was appointed to the International Court of Justice (at The Hague). He was instrumental in formulating the 1906 agreements on Moroccan independence during the Algeciras Conference. In 1919 he was France's representative to the League of Nations, emerging as its champion. He was known as a leading spokesman for the social theory of solidarism, which stressed the quasi-contractual nature of society and the essential obligations of all men to it.

His publications include Solidarité (1896), La Politique de la prévoyance sociale, 2 vol. (1914–19; “The Politics of Social Planning”), Le Pacte de 1919 et la Société des Nations (1919), and L'Oeuvre de la Société des Nations, 1920–1923 (1923; “The Work of the League of Nations”).