Chapin is an unincorporated community and census-designated place in northern Franklin County, Iowa, United States. It lies along local roads just off U.S. Route 65, north of the city of Hampton, the county seat of Franklin County. Its elevation is 1,155 feet (352 m), and it is located at (42°50′1″N93°13′20″W) (42.8335814, -93.2221464).