Grantsdale is an unincorporated community in Ravalli County, Montana, United States. Grantsdale is located near U.S. Route 93 and Montana Highway 38, south of Hamilton. The community had a post office until October 29, 1988; it retains its own ZIP code, 59835.
Initially called Skalkaho Creek, the town became Grantsdale in about 1888 after H. H. Grant, the town's founder.