2019 SU3

 is a very small near-Earth asteroid of the Apollo group, first observed by the Asteroid Terrestrial-impact Last Alert System at Haleakala Observatory on 23 September 2019. It was briefly listed on the Risk List of the European Space Agency. With a 18-day observation arc, the nominal orbit passes 0.02 AU from Earth on 27 September 2084. It was removed from the Sentry Risk Table on 12 October 2019.

Based on calculations with a shorter observation arc, the asteroid could have passed very close to Earth, about 6,000 mi, in mid-September, 2084. According to astronomers, "Its small size of about 15 m would result in limited consequences even in case of impact."