The sterotypical images of a witch includes the typical tall, black, pointed hat with a broad rim. There are different theories as to the origin of this stereotype. The witch's hat may go back to antiquity.

Ancient Etruscan coins from the city of Luna have a head on one side which may be the goddess Diana. The head wears a brimless, conical hat.  

In medieval woodcuts and drawings, witches are depicted wearing various costumes of the times, including headscarves and hats of different fashions. Many are shown bareheaded, with locks flying in the wind.  

It is also possible that the witch's hat is an exaggeration of the tall, conical "dunce's hat" that was popular in the royal courts of the 15th century or the tall but blunt-topped hats worn by Puritans and the Welsh.