Los Glaciares National Park (Spanish: Parque Nacional Los Glaciares) is a federal protected area in Santa Cruz Province, Argentina.

The park covers an area of 726,927 ha (7,269.27 km²; 2,806.68 sq mi), making it the largest national park in the country. Established on 11 May 1937, it hosts a representative sample of Magellanic subpolar forest and west Patagonian steppe biodiversity in good state of conservation. In 1981, it was declared a World Heritage Site by UNESCO.

The park's name refers to the giant ice cap in the Andes, the largest outside of Antarctica, Greenland and Iceland, feeding 47 large glaciers, of which 13 flow towards the Pacific Ocean. In other parts of the world, glaciers start at a height of at least 2,500 m (8,200 ft) above mean sea level, but due to the size of the ice cap, these glaciers begin at only 1,500 m (4,900 ft), sliding down to 200 m (660 ft). Los Glaciares borders Torres del Paine National Park to the south in Chilean territory.