Milton is a town in Strafford County, New Hampshire, United States. The population was 4,482 at the 2020 census. A manufacturing, resort and residential town, Milton includes the village of Milton Mills. The primary village in town, where 593 people resided at the 2020 census, is defined as the Milton census-designated place, and is located along New Ha…Milton is a town in Strafford County, New Hampshire, United States. The population was 4,482 at the 2020 census. A manufacturing, resort and residential town, Milton includes the village of Milton Mills. The primary village in town, where 593 people resided at the 2020 census, is defined as the Milton census-designated place, and is located along New Hampshire Route 125 and the Salmon Falls River, just north of Route 75.