Château de Noaillac, Medieval historic monument in Penne-d'Agenais, France.

Château de Noaillac is a castle in Penne-d'Agenais built of light gray ashlar stone. Its main facade has two rows of rectangular white-framed windows, under a pitched roof of reddish-brown tiles with a straight masonry chimney on the left. A square tower projects forward on the right, capped by a steeper pyramidal roof of the same tiles and pierced by two vertical rows of small square windows. The lower walls are partly hidden by foliage.

A Romanesque tower was built at the end of the 12th century and formed the castle's core. Over the following centuries it was expanded and altered by noble families until it reached its present form.

The castle demonstrates the evolution of architectural styles and noble lifestyles through the centuries in the Lot-et-Garonne region.

The hamlet of Noaillac lies about 2.5 km east of Penne-d'Agenais, north of the D 661 toward Dausse; the lane leading to the castle starts in Dausse. The castle is a private property and cannot be visited inside.

The Romanesque tower at the core, built in the late 12th or early 13th century, can only be seen from inside the castle, since later building work encased it. The 1830 cadastral survey records no additions after that date, so the plan visible today matches the early 19th-century state.