The Conquest of the Desert (Spanish: Conquista del desierto) is a military campaign directed mainly by General Julio Argentino Roca in the 1870s with the intent to establish Argentine dominance over Patagonia, which is inhabited by indigenous peoples.

Under General Roca, the so-called Conquest of the Desert extends Argentine power into Patagonia and ends the possibility of Chilean expansion there.

Argentine troops kill more than one thousand enemy combatants and displace over fifteen thousand more from their traditional lands.

Ethnic European settlers develop the lands for agriculture, turning it into a breadbasket that will make Argentina an agricultural superpower in the early twentieth century.

The conquest is paralleled by a similar campaign in Chile called the Occupation of Araucanía.

The Conquest is highly controversial: apologists will describe the Conquest as bringing civilization, while revisionists will label  it a genocide.

The Conquest is commemorated on the 100 peso bill in Argentina.