Ange-Jacques Gabriel (French pronunciation: [ɑ̃ʒ ʒak ɡabʁijɛl]; 23 October 1698 – 4 January 1782) was the principal architect of King Louis XV of France.

His major works included the Place de la Concorde, the École Militaire, and the Petit Trianon and opera theater at the Palace of Versailles.

Gabriel's design, combining elements of the earlier schemes, left the view toward the Seine open, and preserved unobstructed the long axis between the Tuileries and the Champs-Élysées.

[2] Louis XV decided in 1751 to create the École Militaire, the first French military academy, to train five hundred young men from poor noble families "gentlemen" in the art of warfare.

[5] The Opera project was revived in 1765 and was accelerated in 1770 for the celebrations of the marriage of the Dauphin, the future Louis XVI, to the Archduchess Marie Antoinette of Austria.

To finish the project quickly and at lower cost, the theater was made entirely of wood, painted to resemble marble, but also giving it exceptionally good acoustics.

The theater was in blue and gold, made in shape of truncated ellipse or oval, surrounded by tiers of boxes, decorated with carved and gilded wood, illuminated by three thousand candles whose light was reflected in mirrors.

Gabriel and his chief architectural engineer, Blaise Arnaud, studied installing a mechanism to hoist the floor of the theater up to the level of the stage, to create an enormous ballroom, but this was never completed.