Campos (kämˈpŏs) [key], city (1996 pop. 391,299), Rio de Janeiro state, SE Brazil, on the Paraíba River near its mouth. It is a transportation hub and the commercial hub of a rich agricultural region producing coffee, cacao, rice, sugarcane, and beans. More than half of the state's sugar output is produced in Campos. There are also distilleries in the city. Campos was founded in the early 17th cent. and under the empire was an important slave center.