Lake Argentino (in Spanish, Lago Argentino) is a freshwater lake located in the Patagonian Шаблон:Provincec, at . It is the biggest freshwater lake in Argentina, with a surface area of 1,466 km² (maximum width: 20 km). It has an average depth of 150 m, and a maximum of 500 m.
The lake lies within the Los Glaciares National Park, in a landscape with numerous glaciers and is fed by the glacial meltwater of several rivers, the water from Lake Viedma brought by the La Leona River, and many mountain streams. Its drainage basin amounts to more than 17,000 km². Waters from Lake Argentino flow into the Atlantic Ocean through the Santa Cruz River.
The glaciers, the nearby town of El Calafate and the lake itself are important touristic destinations. The lake in particular is appreciated for fishing. Perch, common galaxias, "puyen grande", lake trout and rainbow trout — in both migratory and sedentary forms — are all found.
Lago Argentino is also the name of the airport Шаблон:Airport codes that serves the area, located at . The town of El Calafate is sometimes called Lago Argentino. This Airport is currently closed and has been replaced by Comandante Armando Tola International Airport Шаблон:Airport codes which serves the town of Calafate and Lago Argentino, with many daily national and international flights.