The Red River Formation is a lithostratigraphical unit of Late Ordovician age in the Williston Basin.

It takes the name from the Red River of the North, and was first described in outcrop in the Tyndall Stone quarries and along the Red River Valley by A.F.

[2][3] The Red River Formation is composed of the following subdivisions from top to base: [1] The Red River Formation reaches a maximum thickness of 215 metres (710 ft) in the center of the Williston Basin.

It extends throughout the Manitoba outcrop belt, and can be correlated throughout the entire Williston Basin area.

[1][4] The Red River Formation is slightly unconformably overlain by the Stony Mountain Formation and sharply overlays the Winnipeg Formation in Manitoba, the Deadwood Formation in western Saskatchewan and the Canadian Shield in northern Manitoba.