Hôtel de Châtillon, Protected private mansion in 4th arrondissement of Paris, France.

The Hôtel de Châtillon is a protected private mansion in Paris's 4th arrondissement featuring grand architectural details such as ornate moldings, tall ceilings, and characteristic French windows across its floors. An internal courtyard forms the heart of its layout and organization.

Claude Chastillon (1559–1616), royal architect, engineer and topographer to Henri IV and Louis XIII, received a plot on the Place Royale and built his own mansion at no. 10 in the early 17th century. The facades and roofs were classified as monuments historiques in 1920, the staircase inscribed in 1953 and the vaulted gallery classified in 1958.

The mansion carries several names: hôtel de Châtillon after its builder Claude Chastillon, but also hôtel de Marie de Lyonne, hôtel de Gagny and Chatainville. Chastillon (1559–1616), royal architect, engineer and topographer to Henri IV and Louis XIII, was also the king's personal "reporter" and helped design the Place Royale, today's Place des Vosges, beside Jacques II Andouet du Cerceau.

The mansion stands at 10 place des Vosges, on the east side of the square between the Hôtel de Fourcy and the Hôtel Lafont. The building is a private condominium, so the facade, the staircase and the vaulted gallery are seen from the square and the shared entrance rather than as a museum visit. The arcades of the square give shelter along the walk.

Claude Chastillon, who built this house for himself at no. 10, worked as royal architect, engineer and topographer to Henri IV and Louis XIII and helped design the Place Royale, today's Place des Vosges. The vaulted gallery was separately listed in 1958, after the facades and roofs in 1920 and the staircase in 1953.