(585310) 2017 YZ1, provisional designation: 2017 YZ1, is a sub-kilometer asteroid on an eccentric orbit, classified as near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 250 meters (800 feet) in diameter. It was first observed on 20 December 2017, by astronomers with the Mount Lemmon Survey at Mount Lemmon Observatory near Tucson, Arizona, in the United States. On 29 January 2018, it passed Earth at 125 lunar distances.