Nimba County is a county in the north-central portion of the West African nation of Liberia. One of 15 counties that comprise the first-level of administrative division in the nation, it has six districts. Sanniquellie serves as the capital with the area of the county measuring , the largest in the nation. As of the 2008 Census, it had a population of 462,026, making it the second most populous county in Liberia.
Named after Neinbaa Tohn Mountain, the tallest mountain in Liberia, Nimba is bordered by Bong and Grand Bassa counties to the west, Rivercess County to the southwest, and Grand Gedeh County to the southeast. The northern and northeastern parts of Nimba borders the nation of Guinea, while the northeast lies along the border of Côte d'Ivoire. Created in 1964, the current County Superintendent, who is the chief administrative officer, is Shirley Brown.