Teylingen Castle (Dutch: Slot Teylingen) is a Dutch castle in the municipality of Teylingen, in Voorhout, near the border with Sassenheim. It is presumably the family keep of the noble family Van Teylingen, from which the Van Brederode family directly descended. The castle was originally built to protect the north-south route in Hollandic territory. Later it became a forester's castle for the forestry of the counts of Holland, starting with William IV, count of Holland.