San Cristóbal is a province in the southern region of Dominican Republic, located west of the capital Santo Domingo. With approximately 642,000 inhabitants, it is the fourth most populated province in the country, only behind Santo Domingo, Santiago and the National District. It borders the provinces Monseñor Nouel (north), Monte Plata (northeast), Santo Domingo (east), Peravia (west) and San José de Ocoa (northwest). The Caribbean Sea borders the province to the south. The provincial capital is the city of San Cristóbal.

The Dominican Republic is divided into thirty-one provincias, while the national capital, Santo Domingo, is contained within its own Distrito Nacional.