Bigfork is an unincorporated community and census-designated place (CDP) in Flathead County, Montana, United States. It is within Montana's Rocky Mountains. The population was 4,270 at the 2010 census, up from 1,421 in 2000.
Bigfork is located in south-central Flathead County at 48°3′55″N 114°4′54″W (48.065214, -114.081700), at the north end of Flathead Lake. The western edge of the CDP is the Flathead River, the primary inflow of the lake. The Swan River flows into Flathead Lake from the east, entering the lake at the center of town. The CDP extends south to the Lake County line; east to Mud Lake, Mud Creek, and the north-south part of the Swan River; and northwards to the roads north of Echo Lake.
Kalispell is 18 miles (29 km) to the northwest, via Montana Highway 35, Montana Highway 82, and U.S. Route 93. Highway 35 runs through the center of Bigfork and proceeds south along the eastern shore of Flathead Lake, rejoining US 93 at Polson.
According to the United States Census Bureau, the Bigfork CDP has a total area of 37.3 square miles (96.6 km2), of which 31.2 square miles (80.9 km2) is land and 6.1 square miles (15.7 km2), or 16.25%, is water.
As of the census of 2010, there were 4270 people, 652 households, and 410 families residing in the CDP. The population density was 247.1 people per square mile (95.4/km2).