Publisher Summary This chapter reviews the Late Cenozoic Quaternary Volcanism in Patagonia and Tierra del Fuego. Patagonia has a vast and significant volcanic history, which started in the Triassic and developed mainly during the Jurassic with the emplacement of extended ignimbritic–rhyolitic plateaus covering the major part of the present area and of the Atlantic continental platform. With the break-up of Gondwana and the beginning of the migration of South America toward the west, during most of the Cretaceous, arc magmatism developed at the western margin of South America. To describe and better understand the evolution of the Late Cenozoic volcanic processes and their relationship with the geodynamic setting, a more extended period from the Late Miocene to the Holocene has been considered in this chapter. However, mostly Pliocene to Holocene volcanic centers and sequences are emphasized as a part of major volcanic provinces. Quaternary volcanism in Patagonia has been strongly influenced by tectonic processes involved in both arc and backarc domains. Tectonic evolution in Patagonia has been characterized by subsequent episodes of compression and transpression–transtension along the volcanic front with localized extension in the backarc region.