Altes Schloss Teufen, Medieval castle in Freienstein-Teufen, Switzerland.

Altes Schloss Teufen is a medieval castle in Freienstein-Teufen, in the canton of Zurich, set on a rise above the village. The main building has stepped gables and is accompanied by an Orangerie on the same property.

In the Middle Ages the lords of Teufen built two castles near the Töss–Rhine confluence, Altenteufen and Hohenteufen. From 1315 the families zum Thor, von Ulm and von Meiss held the low jurisdiction over theft and misdemeanours. In 1638 the von Meiss built a new castle with a stepped gable about 800 m southwest of Altenteufen; the 1798 French invasion and the Helvetian Republic ended their judicial rights.

The castle's stepped gables are the most visible feature from the village below, giving Freienstein-Teufen a recognizable roofline. Visitors walking through the area can easily spot how the building stands apart from the surrounding houses in both size and form.

The site lies on a spur above the road from Teufen down to Freienstein, southeast of the village, so access is on foot or by car along that road. The grounds are private property; the former estate is still run as a wine estate by the descendants of Johann Jakob Keller.

The castle passed through the families zum Thor (1315–1550), von Ulm (1550–1600) and von Meiss (1600–1798), who held the lower jurisdiction over theft and minor offences. In 1808 Salomon Landolt, the bailiff of Greifensee immortalised in Gottfried Keller's novella, lived at the castle after selling his estate in Zurich's Enge quarter.