A diadem is a type of crown.
Diadem may also refer to:
Maritime , several vessels of the Royal Navy Diadem (ship), several merchant vessels
Arts and entertainment Diadem (board game), a 1981 science fiction game Diadem, a science fiction series by John Peel The Diadem Saga, a science fiction series by Jo Clayton "Diadems", a song by Megadeth on the soundtrack for the film Demon Knight (soundtrack) "Diadem", a tune used for the hymn "All Hail the Power of Jesus' Name" The Diadem, a 1969 short movie starring Diana Rigg
Animals Diademed monkey Diadem roundleaf bat Mograbin diadem snake Diadem spider Diadems, the butterfly genus Hypolimnas Diadem (horse), a 20th-century Thoroughbred racehorse
Other uses Diadem (star), a star in the constellation Coma Berenices Operation Diadem, a military operation in World War II's Italian Campaign Diadem Peak, a mountain in Alberta, Canada DIAdem, a technical software for managing, analyzing, and reporting technical data from National Instruments
See also Diadema (disambiguation) Diiadem, a real housewife