Grottoes is a town in Rockingham and Augusta counties in the Commonwealth of Virginia. The population was 2,899 at the 2020 census. The town lies right on the border with Augusta County, and several commercial, residential, and recreational lots have portions within Augusta County. The town is part of the Harrisonburg Metropolitan Statistical Area, while the small portion that extends into Augusta County is part of the Staunton–Waynesboro Micropolitan Statistical Area.