James Ferguson (August 31, 1797 – September 26, 1867) was a Scottish-born American astronomer and engineer, who made the first discovery of an asteroid from North America (31 Euphrosyne). Starting in 1847, he worked at the U.S. Naval Observatory in Washington, DC. As an engineer, he helped to build the Erie canal.
In 1850, he "lost" a star that he had been observing, which Lt. Matthew Maury, the superintendent of the Observatory, claimed was evidence for a 9th planet (Pluto had not yet been discovered). In 1878, however, CHF Peters, director of the Hamilton College Observatory in New York, showed that the star had not in fact vanished, and that the previous results had been due to human error.
The asteroid 1745 Ferguson, discovered from the same observatory, was later named in his honour.