The Huincul Formation is a geologic formation that outcrops in Río Negro and Neuquén provinces of Argentina. It is the second formation in the Río Limay Subgroup, the oldest subgroup within the Neuquén Group. Formerly that subgroup was treated as a formation, and the Huincul Formation was known as the Huincul Member. The type locality of the Huincul Formation is near the town of Plaza Huincul in Neuquén province. This formation conformably overlies the Candeleros Formation, and it is in turn overlain by the Lisandro Formation.