The Muskwa Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.

It takes the name from Muskwa River, and was first described in the Western National Gas Fort Nelson a-95-J/94-J-10 well by F.F. Gray and J.R. Kassube, in 1963.

The Muskwa Formation is composed of bituminous shale. Pyrite is a common accessory mineral.

Gas is produced from the Muskwa Formation shales in the Horn River Basin in the Greater Sierra oil field in north-eastern British Columbia. Horizontal drilling and fracturing techniques are used to extract the gas from the low permeability shales (see Shale gas).

The Muskwa Formation occurs in northern Alberta, north-eastern British Columbia and in the southern part of the Northwest Territories, and typically has a thickness of 34 metres (110 ft).

The Muskwa Formation is a sub-unit of the Horn River Formation; it is conformably overlain by the Fort Simpson Formation and conformably underlain by the Otter Park Member.

• Muskwa Ranges