Tivoli Castle (Slovene: Grad Tivoli), originally called Podturn Manor (German: Schloss Unterthurn,Slovene: Grad Pod turnom), is a mansion in Ljubljana, the capital of Slovenia.
The mansion is located in the city's Tivoli Park (the part in the Rožnik District), northwest of (and visible from) the city centre, at the foot of Rožnik Hill. It is the terminus of the Jakopič Promenade (formerly the Lantieri Promenade), itself the continuation of Cankar Street.
An alpine-style building called the Švicarija (German: Schweitzerhaus 'the Swiss House', formerly the Tivoli Hotel) stands behind the mansion. The Jesenko Nature Trail leads past it.
In the early 15th century, a tower stood in the woods above the site; it was owned by Georg Apfalterer, an ally of Duke Frederick (later Holy Roman Emperor Frederick III). The tower was destroyed by Frederick II, Count of Celje in 1440, but was the source of the original name of the castle: German Schloss Unterthurn and Slovene Grad Pod turnom, both literally 'castle below the tower'.
The current structure was built in the 17th century atop the ruins of a previous Renaissance-period castle, the mansion was initially owned by the Jesuits, but came into the possession of the Diocese of Ljubljana following the 1773 suppression of the Jesuit order. Used as the bishop's summer residence, it was surrounded with orchards.