Cleydael Castle, locally known as Kasteel Cleydael, lies west of the town of Aartselaar, in the province of Antwerp in the Flemish region in Belgium.

Cleydael Castle probably already existed in 1259 when it was owned by the Sanders van Hemessen family. It was first mentioned in 1372 when it was owned by Geeraert van der Elst. Ownership of the castle was disputed between the Sanders and Van der Elst families and in the 15th century the Sanders family retrieved the castle.

During the 16th century the castle had several owners who all adapted it to their liking. One of them was Antonio del Rio in 1556, who was the treasurer of seizures appointed by Fernando Álvarez de Toledo, 3rd Duke of Alba and Governor of the Netherlands. In 1576 the castle was besieged and plundered by the troops of the States General of the Netherlands, led by Philip de Lalaing. This forced Del Rio to flee back to Spain. After that, the damaged castle served as a home for vagabonds until 1592.

In 1613 Cleydael Castle was acquired by the Hellemans family who subsequently restored it. During the next centuries a long list of owners followed, until after WW I when it was bought by an Antwerp shipowner. He had the castle restored in the 1950s.

Cleydael Castle is a square and moated castle, with one square and 3 round corner towers. The square tower is the oldest part of the castle. It has a rectangular bailey which was also moated until 1806.

At present the castle is private property and is rented out as a party and dinner location. The domain around the castle is now used as a golf club, which has its clubhouse in the buildings on the bailey. Therefore the castle can not be visited. A very nice castle.