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 km (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 province originally covered the once-independent indigenous territory of Araucanía, but this was afterward divided into four provinces. It is devoted largely to agricultural pursuits. 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.

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

The province is composed of seven communes, each governed by a municipality consisting of an elected alcalde and municipal council.

According to the 2002 census by the National Statistics Institute (INE), the province spans an area of 5,457.2 km (2,107 sq mi) and had a population of 157,255 inhabitants (79,263 men and 77,992 women), giving it a population density of 28.8/km (75/sq mi). Of these, 117,569 (74.8%) lived in urban areas and 39,686 (25.2%) in rural areas. Between the 1992 and 2002 censuses, the population grew by 5% (7,554 persons).