U.S. Customhouse is a historic customhouse located at Oswego in Oswego County, New York. It is a three-story, flat roofed, rectangular stone building flanked by identical two-story wings. The original structure was built in 1858 and the wings added in 1935. It was designed by architect Ammi B. Young (1798–1874). It was listed on the National Register of Historic Places in 1976.