Isla de los Estados, located in the Southwestern Atlantic 24 km east of Tierra del Fuego, is a Provincial Protected Area. Since the XIX century, several scientific expeditions have collected biological samples from the island; however, studies specifically focused on marine molluscs remain limited, with available data scattered across various sources. This study compiles existing information on benthic mollusc species richness from Isla de los Estados and analyzes the composition of the assemblage, along with its faunistic affinities with Patagonia and Antarctica. A total of 166 species are recorded, including 96 species of gastropods, 48 bivalves, 12 polyplacophora, 7 solenogastres, and 3 cephalopods. Most species are known from the intertidal and shallow subtidal zones (<50 m depth), with only 56 species occurring below 100 m. More than 90% of the species are shared with Patagonia and/or the Malvinas Islands, supporting the classification of the island within the Magellan Province. Notably, 57% of the species currently known from Isla de los Estados are represented by only one or two records, highlighting the incomplete state of knowledge regarding the island’s molluscan fauna.