Great Falls is the third most populous city in the U.S. state of Montana and the county seat of Cascade County. The population was 60,442 according to the 2020 census. The city covers an area of 22.9 square miles (59 km2) and is the principal city of the Great Falls, Montana, Metropolitan Statistical Area, which encompasses all of Cascade County. The Great Falls MSA's population was 84,414 according to the 2020 census.