The province comprises the extreme southern part of Isla Grande de Tierra del Fuego (south of the Cordillera Darwin), the islands south and west of Isla Grande (Diego Ramírez Islands), and Chile's claims in Antarctica.

[4] The province is administratively divided into two communes (comunas): Cabo de Hornos, located at the southern tip of South America, and Antártica, a wedge-shaped claim of Antarctica, which is not internationally recognized.

Daniel Fernando Valdebenito Contreras (PS) Ángela Barría Barrientos (RN) Juan Velásquez (PS) Carolina Guenel González (DC) Francis Delgado Ibaceta (RN) Paola Speake Ojeda (DC) The Municipality of Cabo de Hornos governs both Antártica and Cabo de Hornos from Cabo de Hornos, making it the only Chilean municipality to currently administer more than one commune.

The Commune of Antártica is practically uninhabited except for research stations of various countries, although Chile maintains a permanent civilian population at Villa Las Estrellas (near Frei Montalva Station), including women and children, a small school, and even a bank, in order to support its territorial claim of the area.

[7] On the first organization of the new conquered territories, Charles V, ruler of the Spanish Empire assigned to Pedro Sancho de la Hoz control over Terra Australis, which included the Southern part of South America, Tierra del Fuego Archipelago, and all southern undiscovered territories (Terra Australis Ignota).