Lake Titicaca (Spanish: Lago Titicaca, Quechua: Titiqaqa Qucha) is a large, deep lake in the Andes on the border of Bolivia and Peru. By volume of water and by surface area, it is the largest lake in South America. Lake Maracaibo has a larger surface area, but it is a tidal bay, not a lake.

It is often called the "highest navigable lake" in the world, with a surface elevation of 3,812 metres (12,507 ft). Although this refers to navigation by large boats, it is generally considered to mean commercial craft. For many years the largest vessel afloat on the lake was the 2,200-ton, 79-metre (259 ft) SS Ollanta. Today the largest vessel is most likely the similarly sized, but broader, train barge/float Manco Capac, operated by PeruRail (berthed, as of 17 June 2013, at 15°50′11″S 70°00′53″W, across the pier from the Ollanta). Numerous smaller bodies of water around the world are at higher elevations