Catamarca, referred to in the provincial constitution as the Province of Catamarca, is one of the twenty-three provinces into which the Argentine Republic is divided. It is also one of the twenty-four self-governing states or first-order jurisdictions that make up the country, and one of the twenty-four national legislative electoral districts. Its capital and most populous city is San Fernando del Valle de Catamarca.

It is located in the northwest of the country, in the Norte Grande Argentino region, bordering Salta to the north, Tucumán and Santiago del Estero to the east, Córdoba to the southeast, La Rioja to the south, and Chile to the west, whose border is determined by the watershed of the Andes mountain range. With 368,000 inhabitants in 2010, it is the fifth least populated province—ahead of La Rioja, La Pampa, Santa Cruz, and Tierra del Fuego, Antarctica, and the South Atlantic Islands, the least populated—and with 3.5 inhabitants/km², the fifth least densely populated, ahead of Río Negro, Chubut, La Pampa, and Santa Cruz, the least densely populated.

It was inhabited by the region's native population for several millennia until the intervention of the Spanish conquistadors in the mid-17th century. Since then, it has received various groups of immigrants, especially Spaniards, although unlike other Argentine provinces, these have not outnumbered the original population. The mixture of both groups gave rise to the province's current population, composed primarily of whites and mestizos.