Big Sandy is a town in Chouteau County, Montana, United States. The population was 605 at the 2020 census. Big Bud 747, the largest farm tractor in the world, was located here from 1997 until 2009, and returned in 2020. The Lewis and Clark Trail, following U.S. Route 87, goes through Big Sandy and in 2011 the town was named in a list of "Most Livable Small Towns" by Montana Outdoors magazine. Big Sandy, Montana also was the home of Pearl Jam bassist Jeff Ament, who built Big Sandy a skatepark.