| Official Name: | Barra do Piraí |
| Nickname: | Valley's pearl |
| Mapsize: | 250px |
| Pushpin Map: | Brazil |
| Pushpin Map Caption: | Location of Barra do Piraí in Brazil |
| Subdivision Type: | Country |
| Subdivision Type1: | Region |
| Subdivision Type2: | State |
| Subdivision Name: |  Brazil |
| Subdivision Name1: | Southeast |
| Subdivision Name2: | Rio de Janeiro |
| Leader Title: | Prefeito |
| Leader Name: | Mário Esteves (PRB) |
| Area Total Km2: | 578.471 |
| Population As Of: | 2020 [1] |
| Population Total: | 100,764 |
| Timezone: | UTC-3 |
| Utc Offset: | -3 |
| Coordinates: | -22.47°N -43.8258°W |
| Elevation M: | 363 |
| Website: | http://www.barradopirai.rj.gov.br |
| Settlement Type: | Municipality |
| Barra do Piraí | |
Barra do Piraí (pronounced as /pt/) is a municipality of the Brazilian state of Rio de Janeiro. It is located at latitude 22º28'12" South and longitude 43º49'32" East. Its population is 100,764 (2020) and its area is 578.471 km².[2] It is 114 km from Rio de Janeiro.
The municipality contains part of the Serra da Concórdia State Park, created in 2002.