| Official Name: | Capitán Sarmiento |
| Pushpin Map: | Argentina |
| Pushpin Label Position: | bottom |
| Pushpin Map Caption: | Location in Argentina |
| Pushpin Mapsize: | 200 |
| Pushpin Mapsize1: | 200 |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Buenos Aires |
| Subdivision Type2: | Partido |
| Subdivision Name2: | Capitán Sarmiento |
| Established Title: | Founded |
| Established Date: | 21 December 1961 |
| Population Total: | 11316 |
| Coordinates: | -34.1667°N -106°W |
| Elevation M: | 54 |
| Postal Code Type: | CPA Base |
| Postal Code: | B B2752 |
| Area Code: | +54 2478 |
Capitán Sarmiento is a town in Buenos Aires Province, Argentina. It is the head town of the Capitán Sarmiento Partido.
The town and partido were established by provincial law on 21 December 1961. It was named after Domingo Fidel Sarmiento, adopted son of former President Domingo Faustino Sarmiento.
The town became widely known in 1995, when a province-wide vote to select a new flag for Buenos Aires Province elected a design made by schoolboys from two schools in Capitán Sarmiento. Governor Eduardo Duhalde later issued a decree declaring the town "Cradle of the flag of Buenos Aires", and in 2011 a monument was erected in the town to commemorate its status as such.[1]