A winged helmet is a helmet decorated with wings, usually on both sides. Ancient depictions of the god Mercury and of Roma (personification of the city) depict them wearing winged helmets, however in the 19th century the winged helmet became widely used to depict ancient Celtic, Germanic and Viking warriors. It was also used in romantic illustrations of legendary Norse gods and heroes. The motif, along with the Horned helmet, became a clichéd signifier of the "barbarian" Northern warrior.
There is some limited evidence of such decorative motifs being used on actual helmets in the ancient world, but these seem to have functioned as ceremonial rather than functional objects. Winged helmets were first used in depictions of the Celts who were described by Diodorus Siculus as wearing helmets with animal motifs,
On their heads they wear bronze helmets which possess large projecting figures lending the appearance of enormous stature to the wearer. In some cases horns form one part with the helmet, while in other cases it is relief figures of the foreparts of birds or quadrupeds.
Today this kind of helmet is commonly believed to have been worn by the Celts. The Celts, however, never used winged helmets. Instead, their helmets were generally conical helmets with protections in both sides, left and right (similar to, and an inspiration along with the Corinthian helmet, for the common Roman helmet).
The ancient depictions of Mercury with a winged helmet are taken to symbolize speed. In modern comic book mythology, this has evolved into the wings present in the helmet or head-portion of the costume of various versions of The Flash.