Cornelius Hyatt (October 10, 1831 - January 2, 1904) was a surveyor active on Long Island around the village of Newtown (Elmhurst), who produced several early plat maps of what would become Astoria, Elmhurst, Woodside, and other nearby neighborhoods as they were developing rapidly at the end of the 19th century. Few details of his life are known, but he appears to have been a longtime resident of the area, present since at least 1850, and was a farmer before - or in addition to - becoming a surveyor and civil engineer. Hyatt appears to have been a considerable landholder himself, including a homestead in the village of Winfield, now Woodside.