US Post Office-Fulton is a historic post office building located at Fulton in Oswego County, New York. It was built in 1912-1915 and enlarged in 1936–1938. It is one of a number of post offices in New York State designed by the Office of the Supervising Architect of the Treasury Department, James Knox Taylor. It is a two-story building with a limestone facade that contains a six-part colonnade with attached Doric order columns set in antis between Doric piers in the Greek Revival style. The lobby features a mural by Caroline S. Rohland in 1942 titled "Father LeMoyne Trying to Convert the Indians on Pathfinder Island." It was listed on the National Register of Historic Places in 1989.