Rabštejnek Castle, Gothic castle ruin in Rabštejnská Lhota, Czech Republic.

Rabštejnek Castle is a two-part ruin on a small rock, consisting of a rectangular outer bailey with a moat and rampart and an oval core. The core was dominated by a square donjon, with a narrow timber building behind it and a semicircular tower on the north side.

Rabštejnek was founded in the first half of the 14th century, indirectly documented in 1390 through Matyáš of Rabštejnek's epithet. After 1405 it passed from the Orle family to Matěj Holec of Nemošice, and in 1547 the town of Chrudim lost it to the royal chamber for its part in the estates' revolt. It was described as deserted by 1585.

The name derives from the German Rabenstein, meaning raven's nest, a reference to the castle's position on a small rock; the Czech form Rabštejnek has been used since around 1450. Ownership alternated among noble families, the king and the town of Chrudim, and the site was reported abandoned by the end of the 16th century.

The ruins remain accessible to visitors throughout the year and are located in the Pardubice Region. The site sits on elevated ground that is reachable on foot.

During the 19th century, sections received hunting lodge windows and sgraffiti decorations in pseudo-Romanesque style. These later additions give the site an unexpected second layer from a different era.