The Paraíba do Sul, or simply termed Paraíba, is a river in southeast Brazil. It flows 1,137 km (706 mi) west to northeast from its farthest source at the source of the river Paraitinga to the sea near Campos dos Goytacazes. The river receives its name when it meets the river Paraibuna at the Paraibuna dam.

The Paraíba Valley is a landform that encompasses the regions: Paraíba Valley Metropolitan Region and Northern Coast, in the state of São Paulo and Sul-Fluminense Region, in the state of Rio de Janeiro, which stands out for concentrating a considerable portion of the Brazilian economy.