Olkusz County (Polish: powiat olkuski) is a unit of territorial administration and local government (powiat) in Lesser Poland Voivodeship, southern 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 Olkusz, which lies 37 kilometres (23 mi) north-west of the regional capital Kraków.

The county covers an area of 622.19 square kilometres (240.2 sq mi).

ZGH Boleslaw is a leading miner and producer of zinc products in eastern Europe.