architect, artist, landscape designer, and engineer, best known for his fantastic designs for private houses and gardens in pre-Revolutionary France.

Bélanger was educated at the Collège de Beauvais, where he was taught physics by the Abbé Nollet and studied architecture under J.-D. Leroy. He visited England at least once, and the sketchbook that survives is a rare record of the view by a French architect of late 18th-century England.

Bélanger was an unusually adept manipulator of social connections. He became the lover of Sophie Arnould, the prima donna of the Paris Opéra, and through her met his most important patron, the Comte d'Artois (Charles X), Louis XVI's youngest brother, who commissioned both the gardens of Beloeil (in Belgium) and Bagatelle. Bélanger completed Bagatelle's pavilion in 64 days in 1777 to win a wager between the Comte and his sister-in-law Marie-Antoinette.

Bélanger's landscaping was a principal force in the development of the so-called English garden in France. His best known gardens are at Beloeil and Bagatelle, and at Neuilly and Méréville. The garden at Bagatelle was described as ridiculous by the Scottish gardener Thomas Blaikie (whose plans Bélanger altered), but Bélanger went even farther in the nearby Folie Saint-James, where he constructed the famous Grand Rocher, an artificial rock with a Doric portico set into it, known in its time as the “eighth wonder of the world.”

The major works of Bélanger's last years were the abattoirs at Rochechouart and the immense cupola of the Halle au Blé (1808–13), the first iron and glass dome in architectural history.