| Lagoa | |
| Settlement Type: | Neighborhood |
| Pushpin Map: | Brazil Rio de Janeiro#Brazil |
| Pushpin Map Caption: | Location in Rio de Janeiro |
| Subdivision Type: | Country |
| Subdivision Name: |  Brazil |
| Subdivision Type1: | State |
| Subdivision Name1: | Rio de Janeiro (RJ) |
| Subdivision Type2: | Municipality/City |
| Subdivision Name2: | Rio de Janeiro |
| Subdivision Type3: | Zone |
| Subdivision Name3: | South Zone |
| Population As Of: | 2010 |
| Population Footnotes: | [1] |
| Population Total: | 21,198 |
| Coordinates: | -22.9703°N -43.2106°W |
Lagoa (English: Lagoon) is an affluent residential neighborhood in Rio de Janeiro, Brazil located around the Rodrigo de Freitas Lagoon. It borders the neighborhoods of Ipanema, Leblon, Copacabana, Gávea, Jardim Botânico, and Humaitá.
It is the third most expensive neighborhood to live in South America. It is also one of the few places in Rio de Janeiro without a favela. The population is of about 18,200 inhabitants. Around Rodrigo de Freitas Lagoon, there is a 7.5 km long cycleway and many parks.