Plzen Region is an administrative unit (kraj) in the western part of Bohemia in the Czech Republic. It is named after its capital Plzen (English Pilsen, ). In terms of area, Plzen region is with 7,561 km² the third largest region in the Czech Republic. However, with the population of 572,459 inhabitants (as of 31 December 2012) it was the ninth most populous region. After the South Bohemian Region it is the second least densely populated region. The region can be roughly divided into two parts: a highly industrialized north-eastern part with a strong engineering tradition around Pilsen  and a more hilly and rural south-western part with smaller-sized manufacturing companies processing natural resources.