Arauco Province (Spanish: Provincia de Arauco) is one of three provinces of the Chilean region of Bío Bío.

It spans a coastal area of 6,366 km2 (2,458 sq mi) just south of the mouth of the Biobío River, the traditional demarcation between the nation's major natural regions, Zona Central and Zona Sur.

The capital Lebu (population 25,000) is situated on the coast about 90 km (56 mi) south of Concepción with which it is connected by rail.

[4] As a province, Arauco is a second-level administrative division of Chile, governed by a provincial governor who is appointed by the president.

According to the 2002 census by the National Statistics Institute (INE), the province spans an area of 5,457.2 km2 (2,107 sq mi)[1] and had a population of 157,255 inhabitants (79,263 men and 77,992 women), giving it a population density of 28.8/km2 (75/sq mi).