Redstone is an unincorporated community in Sheridan County, Montana, United States. As of the 2020 census, Redstone had a population of 13. Redstone is located on Montana Highway 5, 18 miles (29 km) west of Plentywood. The community had a post office from 1903 until March 9, 2013; it still has its own ZIP code, 59257.