Rivercess County is a county in the south-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. Cesstos City serves as the capital with the area of the county measuring . As of the 2008 Census, it had a population of 71,509, making it the third least most populous county in Liberia.
Eighth largest in size, it is bordered by Grand Bassa County to the west, Nimba County on the northeast, and Sinoe County to the southeast. The southern part of Rivercess lies on the Atlantic Ocean. Created in 1984, the current County Superintendent is B. Rancy Ziankahn.