Granite County is a county located in the U.S. state of Montana. As of the 2020 census, the population was 3,309. Its county seat is Philipsburg. The county was founded in 1893, and was named for a mountain which contains the Granite Mountain silver mine.

Philipsburg is a town in and the county seat of Granite County, Montana, United States. The population was 841 at the 2020 census. The town was named after the famous mining engineer Philip Deidesheimer, who designed and supervised the construction of the ore smelter around which the town originally formed. He platted the townsite in 1867.