São Borja is a city in the Brazilian state of Rio Grande do Sul.

São Borja is the oldest municipality in the Brazilian state of Rio Grande do Sul and was founded in 1682 by the Jesuits as the first of the Seven Places of the Missions, and named São Francisco de Borja, in honor of Saint Francis Borgia.

It is situated on the Western Frontier of Rio Grande do Sul on the border with Argentina which is defined by the Uruguay River (Portuguese spelling of the river: Uruguai).

Served also by São Borja Airport, the city is linked to the Argentine city of Santo Tomé through the Integration Bridge.

This geographical article relating to Rio Grande do Sul is a stub.