Schloss Seggau is a castle situated in Seggauberg in southern Styria, Austria.

It is located on a wooded hill overlooking the town of Leibnitz.

[1] The area around Schloss Seggau has been settled since at least the Roman era, as demonstrated by the impressive lapidarium which has survived from that period.

The upper castle was built by the Archbishopric of Salzburg in the twelfth century as a base for missions and supervision and this original structure was expanded in 1218 by the bishops of Seckau.

The castles were completed in their present form under Bishop Johann Ernst, Count of Thun, in the latter half of the seventeenth century.