Papuk is the largest mountain in the Slavonia region in eastern Croatia, near the city of Požega. It extends between Bilogora to the northwest, Krndija to the east, and Ravna gora and Psunj to the southwest.
The highest peak is the eponymous peak at 953 m.a.s.l.
The area of Papuk is designated a nature park (park prirode), a kind of protected area in Croatia.
At the seventh European Geopark Network Open Conference, hosted by North West Highlands Geopark in September 2007, the Papuk Geopark became the first Croatian Geopark and 30th member of the European and UNESCO Global Geoparks Network.
Geopark Papuk was awarded licence second time from UNESCO in 2011.