The Belgian UFO wave refers to a series of sightings of triangular UFOs in Belgium, which lasted from 29 November 1989 to April 1990.

The main picture of the Belgian UFO Wave is the Petit-Rechain picture. For 20 years, the ufological organisation Société Belge d'Etudes des Phénomènes Spatiaux (SOBEPS) claimed that this picture was genuine, and to this day it remains so.