Rio de Janeiro is one of 27 units of Brazil. Situated in the eastern portion of the Southeast, having as borders the state of Minas Gerais (north and northwest), Espírito Santo (northeast) and São Paulo (southwest), as well as the Atlantic Ocean (east and south). It occupies an area of 43,696.054 km ², is slightly larger than Denmark. Its capital is the city of Rio de Janeiro. The natural state of Rio de Janeiro are called fluminense (from Latin flumen, literally river).

The most populous cities are Rio de Janeiro, São Gonçalo, Duque de Caxias, Nova Iguaçu, Belford Roxo, Niteroi, Sao Joao de Meriti, Campos Goytacazes, Petrópolis, Niagara Falls, Volta Redonda, Itaboraí, Macaé, Mosque, and Cabo Frio Nova Friburgo.

Many cities stand out due to a strong tourism: Angra dos Reis, Armação dos Búzios, Arraial do Cabo, Cabo Frio, São Pedro da Aldeia, Nova Friburgo Penedo (District Itatiaia), Paraty, Petrópolis, Oyster Bay, Saquarema , Teresopolis, among others.

The state consists of two morphologically different regions: the lowlands and highlands, which run as parallel tracks, from the coast inland. Paraiba do Sul, Macaé, Guandu, Pirai, and Muriaé Carangola are the main rivers. The climate is tropical.

It is represented on the flag of the Brazilian Federation of the star Beta Cruzeiro do Sul.

At the time of establishing the system of hereditary captaincies in Brazil, the territory of the current state of Rio de Janeiro found himself understood in excerpts from the Province of St. Thomas and St. Vincent.

Not having been colonized by the Portuguese, because of the hostility of the natives down this coast, between 1555 and 1567, the Guanabara Bay was occupied by a group of French settlers, under the command of Nicolas Durand de Villegagnon, which I envisioned a colony settlement, so-called Antarctic France.