Château de Bien-Assis, Medieval manor house in Montluçon, France.

Château de Bien-Assis is a 15th-century fortified house in Montluçon, set on the edge of the plateau above the Étourneaux stream. Its rectangular main building has two rooms per floor and a square stair tower with a projecting circular turret at the centre of the façade. The tower is topped by a dark pyramidal roof with a slender spire and a small pointed turret at its left corner.

The seigneurie is attested from 1460 with Robert, seigneur de Bien-Assis; Colas de Peret, also called Nicolas Dupeyret, held it in 1481. The building's style dates it to the second half of the 15th century. It passed through the Chasauvert, Mercier, Tardé, Alamargot and La Saigne de Saint-Georges families, then to Mme Sarret, who sold it to Jean and Richard de Montaignac. After expropriation by Montluçon it was bought in 1970 by the Amis de Montluçon, saving it from demolition.

The castle's name comes from the seigneurie held by Robert de Bien-Assis from 1460, and the building gave its name to the surrounding residential district west of Montluçon. Since 1970 the Amis de Montluçon have kept collections here, shown in a permanent first-floor exhibition on Montluçon and its surroundings from prehistory to the 20th century.

The ground-floor rooms host a temporary exhibition each June, while the first floor holds a permanent display on Montluçon from prehistory to the 20th century. The vaulted cellar and chapel contain a lapidary collection of stones recovered from the Château jaune, demolished in 1963.

The vaulted cellar and chapel hold a lapidary collection: stones salvaged from the Château jaune, a bourgeois house at the foot of the ducs de Bourbon castle, demolished in 1963. The 1993 Prix Émile-Mâle rewarded the restoration of the building.