The Phoenix Lights (sometimes called the "Lights Over Phoenix") were a series of widely sighted unidentified flying objects observed in the skies over the southwestern U.S. states of Arizona and Nevada on March 13, 1997.^[2]

Lights of varying descriptions were seen between 7:30–10:30 p.m. MST, in a space of about 300 miles (480 km), from the Nevada line, through Phoenix, to the edge of Tucson. Some witnesses described seeing what appeared to be a huge carpenter's square-shaped UFO containing five spherical lights. There were two distinct events involved in the incident: a triangular formation of lights seen to pass over the state, and a series of stationary lights seen in the Phoenix area.^[3][4]

Both sightings were due to aircraft participating in Operation Snowbird, a pilot training program operated in winter by the Air National Guard out of Davis-Monthan Air Force Base in Tucson, Arizona. The first light group was later identified as a formation of A-10 Thunderbolt II aircraft flying over Phoenix while returning to Davis-Monthan. The second group of lights were identified by Robert Sheaffer as illumination flares dropped by another flight of A-10 aircraft that were on training exercises at the Barry Goldwater Range in southwest Arizona.^[5] Fife Symington, governor of Arizona at the time, years later recounted witnessing the incident, describing it as "otherworldly."^[3][4]

Reports of similar lights arose in 2007 and 2008 and were attributed to military flares dropped by fighter aircraft at Luke Air Force Base,^[6] and flares attached to helium balloons released by a civilian, respectively.^[7]