Rosário Oeste is a municipality in the state of Mato Grosso, in the Central-West Region of Brazil. It is one of the many municipalities that make up this large, sparsely populated interior state, which forms part of Brazil's Centre-West.
The municipality sits in the western-central portion of Mato Grosso, a state whose landscape is dominated by the Pantanal wetlands, the Cerrado savanna, and areas of Amazon rainforest along its northern edge. Rosário Oeste lies within this broader interior setting, well inland from Brazil's Atlantic coast.
Like other municipalities in Mato Grosso, Rosário Oeste is administered as a local government unit with its own municipal seat and surrounding rural area. The state as a whole is known for its agricultural frontier and for the Pantanal, one of the world's largest tropical wetland areas, though the municipality's specific economy and attractions are not detailed in the available reference material.