Białobrzegi County is a unit of territorial administration and local government (powiat) in Masovian Voivodeship, east-central Poland. It came into being on January 1, 1999, as a result of the Polish local government reforms passed in 1998. Its administrative seat and largest town is Białobrzegi, which lies 63 km south of Warsaw. The only other town in the county is Wyśmierzyce, lying 10 km west of Białobrzegi. The county covers an area of 639.28 km2. As of 2019 its total population is 33,524, out of which the population of Białobrzegi is 6,951, that of Wyśmierzyce is 885, and the rural population is 25,688.

Neighbouring counties

Białobrzegi County is bordered by Grójec County to the north, Kozienice County to the east, Radom County to the south and Przysucha County to the south-west.

Administrative division

The county is subdivided into six gminas (two urban-rural and four rural). These are listed in the following table, in descending order of population.