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 2001 census [INDEC] 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)

• Municipal information: Municipal Affairs Federal Institute (IFAM), Municipal Affairs Secretariat, Ministry of Interior, Argentina. (in Spanish)
• "Sastre, Santa Fe". Santa Fe provincial government.

• es:Sastre y Ortiz (Santa Fe)

• Sastre's map