| Official Name: | São Gonçalo do Piauí |
| Settlement Type: | Municipality |
| Pushpin Map: | Brazil |
| Pushpin Map Caption: | Location in Brazil |
| Coordinates: | -5.9933°N -42.7028°W |
| Subdivision Type: | Country |
| Subdivision Name: | Brazil |
| Subdivision Type1: | Region |
| Subdivision Name1: | Northeast |
| Subdivision Type2: | State |
| Subdivision Name2: | Piauí |
| Subdivision Type3: | Mesoregion |
| Subdivision Name3: | Centro-Norte Piauiense |
| Subdivision Type4: | Microregion |
| Subdivision Name4: | Médio Parnaíba Piauiense |
| Subdivision Type5: | Metrop. region |
| Leader Title: | Mayor |
| Elevation M: | 240 |
| Area Total Km2: | 150.22 |
| Population Total: | 5,030 |
| Population As Of: | 2020 [1] |
| Population Density Km2: | auto |
| Timezone1: | BRT |
| Utc Offset1: | -3 |
| Postal Code Type: | Postal code |
| Postal Code: | 64438-xxx |
| Area Code Type: | Area code |
São Gonçalo do Piauí (first part, Portuguese meaning "San Goncalo of Piaui") is a municipality of the Brazilian state of Piaui. It is located at an altitude of 270 meters. The population is 5,030 (2020 est.) in an area of 150.22 km2.[2] After a plebiscite held in 1995, part of the municipality was split off and became the municipality of Santo Antônio dos Milagres.