The Lago Colhué Huapí Formation is a Late Cretaceous geologic formation of the Chubut Group in the Golfo San Jorge Basin in Patagonia, Argentina. The formation, named after Lake Colhué Huapí, is overlain by the Salamanca Formation of the Río Chico Group and in some areas by the Laguna Palacios Formation.The strata of the Lago Colhué Huapé Formation were thought to pertain to the Bajo Barreal Formation, but are now recognized as a distinct stratigraphic unit in their own right.
Taxa recovered from the Lago Colhué Huapí Formation include the sauropods Aeolosaurus colhuehaupiensis, Argyrosaurus, and Elaltitan, as well as the hadrosaurid Secernosaurus and the probable elasmarian ornithopod Sektensaurus. The ceratopsian Notoceratops was also present. The top predator was an unnamed megaraptorid.