El Ranco Province[4] (Spanish: Provincia del Ranco) is one of two provinces of the southern Chilean region of Los Ríos.

The lake is drained by the Bueno River, on which basin lies most of the province.

As a second-level administrative division, the province comprises four communes, each with its own governing municipality.

Alsono Pérez de Arce Carrasco is the provincial governor.

According to the 2002 census by the National Statistics Institute (INE), the province spans an area of 8,232.3 km2 (3,179 sq mi)[1] and had a population of 97,153 inhabitants (49,485 men and 47,668 women), giving it a population density of 11.8/km2 (31/sq mi).