| Sastre | |
| Native Name Lang: | es |
| Settlement Type: | Town |
| Pushpin Map: | Argentina |
| Pushpin Map Caption: | Location of Sastre in Argentina |
| Coordinates: | -31.75°N -111°W |
| Subdivision Type: | Country |
| Subdivision Name: | Argentina |
| Subdivision Type1: | Province |
| Subdivision Name1: | Santa Fe |
| Subdivision Type2: | Department |
| Subdivision Name2: | San Martín |
| Leader Party: | Justicialist Party |
| Leader Title: | Mayor |
| Leader Name: | Maria del Carmen Brunazzo |
| Unit Pref: | Metric |
| Area Total Km2: | 289 |
| Population Total: | 5534 |
| Population Density Km2: | auto |
| Timezone1: | ART |
| Utc Offset1: | -3 |
| Postal Code Type: | CPA base |
| Postal Code: | S2440 |
| Area Code Type: | Dialing code |
| Area Code: | +54 3406 |
Sastre is a town (comuna) in the west of the province of Santa Fe, Argentina, 139 km west from the provincial capital. It had about 5,500 inhabitants at the and it is the head town of the San Martín Department.
It is named after Marcos Sastre, a renowned Argentine lawyer, writer, and educator. Miguel Brascó, the noted Argentine writer and food critic, hails from Sastre.
Sastre is twinned with:
Alba, Piedmont, Italy (1988)