Gbarpolu is in the northern portion of Liberia. One of 15 counties that comprise the first-level of administrative division in the nation, it has six districts. Bopulu serves as the capital with the area of the county measuring 9,689 square kilometres (3,741 sq mi).As of the 2008 Census, it had a population of 83,758, making it the eleventh most populous county in Liberia.

Created in 2001 when it was split from Lofa County, Gbarpolu is the youngest county in Liberia, The county is bordered by Grand Cape Mount County to the west, Bomi County to the southwest, Bong County to the south, and Lofa County to the east and north. The northwest part of Gbarpolu borders the nation of Sierra Leone.

The majority of Gbarpolu consists of forest. Mining was the primary economic activity prior to the Liberian Civil War, in addition to subsistence farming.

The County Superintendent is Gertrude Lamine.