Żagań County (powiat żagański) is a unit of territorial administration and local government (powiat) in Lubusz Voivodeship, western 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 Żagań, which lies 39 km south of Zielona Góra and 124 km south of Gorzów Wielkopolski. The county contains four other towns: Szprotawa, lying 14 km south-east of Żagań, Iłowa, lying 15 km south-west of Żagań, Małomice, lying 12 km south-east of Żagań, and Gozdnica, 25 km south-west of Żagań.
The county covers an area of 1131.29 km2. As of 2019 its total population is 79,297. The most populated towns are Żagań with 25,731 inhabitants and Szprotawa with 11,820 inhabitants.
Żagań County is bordered by Zielona Góra County to the north, Nowa Sól County to the north-east, Głogów County and Polkowice County to the east, Bolesławiec County and Zgorzelec County to the south, and Żary County to the west.