Fulton County is a county in the U.S. state of New York. It forms part of the state's Mohawk Valley region. Its county seat is Johnstown. At the 2020 U.S. census, the county had a population of 53,324. The county is named in honor of Robert Fulton, who is widely credited with developing the first commercially successful steamboat. The county is part of the Mohawk Valley region of the state.