The hennin was a headdress in the shape of a cone, steeple, or truncated cone worn in the Late Middle Ages by European women of the nobility. They were most common in Burgundy and France, but also elsewhere, especially at the English courts, and in Northern Europe, Hungary and Poland. They were little seen in Italy. It is unclear what styles the word hennin described at the time, though it is recorded as being used in French areas in 1428, probably before the conical style appeared. The word does not appear in English until the 19th century. The term is therefore used by some writers on costume for other female head-dresses of the period.

Headgear, headwear, or headdress is any element of clothing which is worn on one's head, including hats, helmets, turbans and many other types. Headgear is worn for many purposes, including protection against the elements, decoration, or for religious or cultural reasons, including social conventions.