Château de la Rochefoucauld, Classical castle in Liancourt, France.

Château de la Rochefoucauld is a classical castle in Liancourt located on Avenue d'Île de France, with remaining structures that showcase 17th-century design. The preserved sections display symmetrical facades and architectural features typical of that period.

Construction of the castle began in the 17th century when the Du Plessis family transformed an older fortress into a grand residence. The structure evolved over time, becoming a lasting landmark in the region's history.

The name comes from the La Rochefoucauld family, though the sources document the earlier seigneurs of Liancourt: Jean Ier de Popincourt took the title sire de Liancourt through his marriage to Claude de Cressonsacq, and the Du Plessis family held the estate afterwards. Charles du Plessis, a Protestant friend of Henri IV, and his wife Antoinette de Pons funded work on the parish church of Saint-Martin, where both were buried in 1620 and 1632 beneath white marble kneeling statues, moved in 1854 to the south chapel.

Only the outbuildings (communs) of the château survive, and they are private property, so they are seen from the public road rather than visited inside. The site lies in the Brêche valley between Creil and Clermont, in the marshland between the Brêche and the Béronnelle. Look for the entrance gateway and terrace wall from the street.

Only the outbuildings of the château survive; they were listed as a monument historique on 3 December 1930. The seigneurial residence itself stood in the marshy meadow between the Brêche and the Béronnelle, on the same spot as the 16th- and 17th-century châteaux that replaced it.