Wonogiri Regency is located in the southeastern part of the Central Java province in Indonesia. It covers an area of 1,904.32 km² and shares borders with Sukoharjo Regency and Karanganyar Regency to the north, East Java Province to the east, the Special Region of Yogyakarta to the west, and the Indian Ocean to the south.
The regency's capital and largest town is Wonogiri, situated approximately 33 km southeast of the metropolis of Surakarta. As of mid-2024, the population of the regency was estimated at 1,054,145. A notable geographical feature within the region is the Gajah Mungkur Reservoir, which covers a surface area of 88 km² in the upper reaches of the Solo River.