Windham is a census-designated place (CDP) in Judith Basin County, Montana, United States. It is in the center of the county along U.S. Route 87, Montana Highway 200 and 3. The town is 6 miles (10 km) southeast of Stanford, the county seat, and 38 miles (61 km) west of Lewistown. As of the 2020 census, Windham had a population of 43.