Villa Mercedes is a city in the province of San Luis, Argentina. It lies on the center-east of the province, on the left-hand banks of the Quinto River, 32 km from the border with Córdoba, on National Route 148, and near the intersection of National Routes 8 and 7. National Route 7 links the city to the provincial capital San Luis, 90 km to the north-west. It had 96,781 inhabitants during the 2001 census [INDEC].
The city was founded by Governor Justo Daract on or around December 1, 1856, as Fortín Constitucional, a mixed civilian-military fort, to protect the territory against attacks by the Ranquel aboriginal tribes. The original name was changed in 1861 to Villa Mercedes by decision of the residents, who had adopted the Virgin of Mercy (Virgen de las Mercedes) as their patron.
Villa Mercedes grew quickly after a railway line from Villa María on the Central Argentine line between Rosario and Córdoba, reached the town in 1875.