Hôtel de Cheusses, Historic private mansion in Rochefort, France.

The Hôtel de Cheusses is a U-shaped stone mansion in Rochefort, built between a courtyard and a garden, with a steep dark grey slate roof and a rounded archway carved "MUSEE DE LA MARINE" above its double wooden door. Its oldest wing, framed by two square pavilions, dates from 1600-1620; a neo-classical portal by engineer Onésime Augias was added between 1749 and 1775. It has housed the national Musée de la Marine since 1978.

Construction took place between 1594 and 1672, and the building later served as headquarters for naval commanders after Louis XIV established the Rochefort naval arsenal. Its development began decades before the town itself was founded.

The building's name comes from Jacques Henri de Cheusses, the last lord of Rochefort, whose wife was Gédéon de Lauzeré's daughter; the estate had been sold under a buyback pact, so he held it as a simple engaged lord. Wood panelling survives in five rooms on the ground floor and upper floor.

The museum occupies the hôtel de Cheusses, entered through the neo-classical portal built by engineer Onésime Augias between 1749 and 1775, flanked by guard posts. The building stands between courtyard and garden, with the carved rococo avant-corps on the east wing facing the court. Wood panelling survives in five rooms on the ground floor and first floor.

The building predates Rochefort itself: Gédéon de Lauzeré erected its first wing between 1600 and 1620, before Colbert chose the site for the royal arsenal in 1666. The town's grid plan was later laid out following the orientation of the hôtel.