Pernik is a city in western Bulgaria (about 20 kilometres (12 miles) south-west of Sofia) with a population of 92,158 as of 2021.

Pernik is the most populated city in western Bulgaria after Sofia. It is the main city of Pernik Province and lies on both banks of the Struma River in the Pernik Valley between the Golo Bardo Mountain, Vitosha Mountain, Lyulin and Viskyar mountains.