Château de Montjean, Manor house in the Montjean plain, Wissous, France.

Château de Montjean is a two-storey manor house of light grey stone blocks with a darker stone base and a low hipped roof. Its long facades have tall rectangular windows with dark grey louvered shutters, and thick green climbing vines cover much of the wall between the windows. A raised terrace with a thin metal canopy on slender columns is reached by a flight of stone steps.

The estate belonged in the 1660s to the noble Jacques de Beauvais; per historian Jean Lebeuf it was later inhabited by a servant of Louis XVI. It was divided into two properties held by General François de Chasseloup-Laubat and the Marquis de Clermont-Gallerande, and the Duke of Aumont resided there from 1824. The present château, built in the early 19th century, was the Clermont-Gallerande property; Chasseloup-Laubat's was destroyed around 1900.

The name Montjean is said to come from the estate's first owner, a nobleman from Montjean-sur-Loire. Today the restored stables are used by the Attelages de Wissous, an association that offers horse-drawn carriage rides through the park.

The château itself is only partly occupied and one part is walled up, so the interior cannot be visited; the building is seen from outside. The surrounding 17-hectare park is classified as a sensitive natural area and is crossed by the Rû de Rungis, which runs underground beneath the fill from the A6 motorway. The restored stables are used by the Attelages de Wissous association.

The estate's stables, restored in the 2010s and 2020s, are used by the Attelages de Wissous, a carriage-driving association formerly called Attelages de Montjean. The main house itself is only partly occupied, with one section walled up, and in 2025 the town launched a call for expressions of interest to renovate it.