One of the five alternating current power grids or interconnections that make up the power grid in North America. The Western Interconnection stretches from western Canada south to Baja California Norte in Mexico, reaching eastward over the Rockies to the Great Plains. The other interconnections are the Eastern Interconnection, the Texas Interconnection, the Alaska Interconnection and the Quebec Interconnection.

The Western Interconnection is overseen by the Western Electricity Coordinating Council, one of the regional councils of the North American Electric Reliability Corporation.