This is a list of notable alleged sightings of unidentified flying objects (UFOs) in the United Kingdom. Many more sightings have become known since the gradual release, between 2008 and 2013, of the Ministry of Defence's UFO sighting reports by the National Archives. In recent years, there have been many sightings of groups of slowly moving lights in the night sky, which can be easily explained as Chinese lanterns. Undertaken between 1997 and 2000, Project Condign concluded that all the investigated sightings of unidentified aerial phenomena in the UK could be attributed to misidentified but explicable objects, or poorly understood natural phenomena.

12th century

13th century

20th century

1940s

1950s

1960s

Wing Commander]] Eric Cox of Hyde when driving from Cadnam to Fordingbridge, in south Hampshire, at 11.05pm, being described as a 'fiery cross'. The other sightings were a few minutes later, and also seen in Wales.

1970s

1980s

1990s–2000

21st century