Rio de Janeiro is a city in Brazil.
Rio de Janeiro may also refer to:
- Rio de Janeiro (state), a state of Brazil
- Greater Rio de Janeiro, the metropolitan area of the city in Brazil
- A former name for Guanabara Bay
- Rio de Janeiro (Bahia), a river in the Brazilian state of Bahia
- Río de Janeiro (Buenos Aires Metro), a metro station in Buenos Aires
- Protocol of Rio de Janeiro, a 1942 international agreement