Fontanet is an unincorporated census-designated place in central Nevins Township, Vigo County, in the U.S. state of Indiana. It lies along Baldwin St., northeast of the city of Terre Haute, the county seat of Vigo County. Its elevation is 614 feet, and it is located at 39°34′34″N 87°14′37″W. Although Fontanet is unincorporated, it has a post office, with the ZIP Code of 47851.Fontanet is part of the Terre Haute Metropolitan Statistical Area.