Niterói is a city of Brazil, in the state of Rio de Janeiro. The population is circa 700,000.

During the period when Rio de Janeiro was the national capital, Niterói served as the capital of the State of Rio de Janeiro, which later was merged with the State of Guanabara (correspondent to the city of Rio de Janeiro).

Anciently spelled Nictheroy, the name means "hidden waters" in the Tupi language. It is 5km near of the Rio de Janeiro city and has one the best quality of life of Brazilian cities. In Niterói there is a famous Modern Art Museum, designed by the famous Brazilian modernist architect Oscar Niemeyer.