Winslow Upton (born in Salem, Massachusetts, 12 October 1853; died Providence, Rhode Island, 8 January 1914) was a United States astronomer.
He graduated from Brown University. He was an assistant at the Harvard Observatory for several years, then assistant engineer of the U. S. Lake Survey, and later computor of the U.S. Naval Observatory and of the U.S. Signal Service. He was appointed professor of astronomy at Brown in 1883. He was a member of the U. S. government eclipse expeditions of 1878 and 1883, also of two private expeditions sent out in 1887 and 1889, and in 1896-97 was attached to the southern station of Harvard University at Arequipa, Peru.