| Official Name: | Três Fronteiras |
| Settlement Type: | Municipality |
| Pushpin Map: | Brazil |
| Pushpin Map Caption: | Location in Brazil |
| Coordinates: | -20.235°N -50.8903°W |
| Subdivision Type: | Country |
| Subdivision Name: | Brazil |
| Subdivision Type1: | Region |
| Subdivision Name1: | Southeast |
| Subdivision Type2: | State |
| Subdivision Name2: | São Paulo |
| Subdivision Type3: | Mesoregion |
| Subdivision Type4: | Microregion |
| Subdivision Type5: | Metrop. region |
| Leader Title: | Mayor |
| Area Total Km2: | 151.59 |
| Population Total: | 5,832 |
| Population As Of: | 2020 [1] |
| Population Density Km2: | auto |
| Timezone1: | BRT |
| Utc Offset1: | -3 |
| Postal Code Type: | Postal code |
| Area Code Type: | Area code |
Três Fronteiras (Portuguese meaning "three borders") is a municipality in the state of São Paulo in Brazil. The population is 5,832 (2020 est.) in an area of 151.59 km².[2] The elevation is 395 m. The name Três Fronteiras refers to the nearby tripoint of the states São Paulo, Minas Gerais and Mato Grosso do Sul, but the municipality does not touch this tripoint. Most of the population are farmers.
In telecommunications, the city was served by Telecomunicações de São Paulo.[3] In July 1998, this company was acquired by Telefónica, which adopted the Vivo brand in 2012. The company is currently an operator of cell phones, fixed lines, internet (fiber optics/4G) and television (satellite and cable).[4]