Tielen Castle, Protected medieval castle in Tielen, Belgium.

Tielen Castle is a medieval fortress in Kasterlee with stone walls, towers, and multiple levels that reveal its defensive purpose. The structure retains significant architectural features from its original period of construction.

A moated watchtower stood here in 1096; the present castle was likely built around 1350 by Hendrik van Duffel on the site of a fortified farm. It passed by marriage and inheritance among noble families until the last lord, Filip van der Gracht de Rommerswael, lost it in the French Revolution. The heirs recovered it in 1826, and it was first sold in 1958.

The castle and the Tielen watermill stayed in the hands of the Lords of Tielen until heirs sold them in the 20th century. The first lord was Jan van Duffel-Berthout, who inherited Tielen in 1320 from Hendrik IV Berthout. The last lord, Filip van der Gracht de Rommerswael, lost the estate to the French Revolution on 7 December 1810; the confiscated goods were returned to his heirs in 1826.

The castle can be located using local maps and is accessible via main roads in the Kasterlee area. It is advisable to check opening hours and visiting conditions in advance before planning a visit.

The castle was sold for the first time only in 1958, after centuries in the hands of the Lords of Tielen and their heirs. In May 2022 it was offered for sale again, with an asking price of 2.5 million euros, after standing empty following the death of Emilienne Verboven.