The Château de Voisins is a neoclassical mansion located in Louveciennes, in the department of Yvelines, France.
In 1696, probably due to its proximity to Versailles, the château was bought by the Marquis de Cavoye, Grand Marshall of the household of Louis XIV.
A granddaughter of Louis XIV and Madame de Montespan, the princess had the château rebuilt to designs of Claude-Nicolas Ledoux.
Circa 1820, a new owner, the Comte de Turtot Hocquart, finding the château old fashioned, had it remodelled.
Following William's death in 1913, his widow retained use of the garden pavilion, but the estate passed to a relative, the banker and collector Robert de Rothschild (1880–1946).