The Rio Cricaré, also known as the Braço Sul do Rio São Mateus, is a significant river system forming the southern arm of the São Mateus River basin in Espírito Santo, Brazil. It serves as a primary drainage for the region, with a catchment area of 2,725 km² within the state. The river is notable for its confluence with another branch at the city of São Mateus, where it gives rise to the main São Mateus River. The river's course is geographically distinctive, meandering through the valley in shapes that resemble the letters "S" and "M," which are the initials of the city of São Mateus. Historically, it has been an important transportation route.