Gilles-Marie Oppenordt (27 July 1672 – 13 March 1742) was a celebrated French designer at the Bâtiments du Roi, the French royal works, and one of the initiators of the Rococo, nicknamed "the French Borromini". He specialized in interior architecture and decoration, though he has been connected with the furniture of Charles Cressent. His surname has also been spelled Oppenord and Oppenort.
Gilles-Marie Oppenordt was born in Paris. His father Alexandre-Jean Oppenord (1639–1713) was an ébéniste, born Cander-Johan Oppen Oordt at Guelders, one of numerous cabinet-makers from the Low Countries who were drawn to Paris by the opportunity of patronage; the elder Oppenord was naturalized in 1679, when he was a menuisier en ebène ("furniture-maker in ebony") at the Manufacture Royale des Gobelins; in 1684 the elder Oppenord was appointed an ébéniste du Roi, with official lodgings in the Galeries du Louvre that had been perquisites in the royal gift of outstanding craftsmen in the luxury trades since the time of king Henri IV.
As a boy Gilles-Marie Oppenord was trained in the studio of Jules Hardouin-Mansart and was sent in 1692 to study as a royal pensioner in Rome for eight years, where he largely ignored the remains of Classical Antiquity and spent his time instead sketching the Baroque sculptural ornaments of the preceding generations, principally those carried out under Bernini and Borromini, and in northern Italy the ornament of Mannerist architects like Pirro Ligorio. Three notebooks of his youthful drawings survive.