Kalispell is a city in and the county seat of Flathead County, Montana, United States. The 2020 census put Kalispell's population at 24,558. The latest estimates put the population at 31,296. Among cities in Montana, it is the 8th largest by area, 7th most populous, and 8th fastest growing from 2010 to 2020. In Montana's northwest region, it is the largest city and the commercial center of the Kalispell Micropolitan Statistical Area. The name Kalispell is a Salish word meaning "flat land above the lake".