The Rendlesham Forest Incident refers to a series of reported sightings of unexplained lights and alleged landing of a craft or multiple craft of unknown origin in Rendlesham Forest, Suffolk, England, in late December 1980, just outside RAF Woodbridge, which was used at the time by the United States Air Force (USAF).

The strange events occurred on the night of December 26, 1980, when a team of servicemen at RAF Woodbridge went to investigate strange lights that had been witnessed descending into the trees. Sergeant Jim Penniston and his team ventured into the forest and reported seeing a strange craft with hieroglyphic-like markings, which Penniston touched and claimed to have received a telepathic message from. Later that night, Lieutenant Colonel Charles I. Halt, the deputy base commander, led a team to investigate the sightings and witnessed unusual lights and beams of light that appeared to move through the trees.

The events have been a subject of controversy, with some people convinced that it was a genuine sighting of multiple unidentified objects, while others are not so sure. The incident has been widely considered as Britain's most extraordinary encounter, and it involved at least a dozen civilians from villages surrounding Rendlesham Forest, a large pine wood in southeast Suffolk.

The incident has been the subject of numerous investigations, including by the UK Ministry of Defense and the United States Air Force. While some explanations have been put forward, no definitive explanation for the Rendlesham Forest Incident has been established to date. The case remains one of the most famous purported UFO sightings in history.