A ghoul is a monster from ancient Arabian folklore that dwells in burial grounds and other uninhabited places. The English word comes from the Arabic name for the creature: الغول ghūl, which literally means "demon". The ghul is a devilish type of jinn believed to be sired by Iblis.

The female form is given as "ghouleh" in Muhawi and Kanaana.The plural is "ghilan".

Ghul is also the name for a desert-dwelling shapeshifting demon that can assume the guise of an animal, especially a hyena. It lures unwary travellers into the desert wastes to slay and devour them. The creature also preys on young children, robs graves, and eats the dead. Because of the latter habit, the word ghoul is sometimes used to refer to an ordinary human such as a grave robber, or to anyone who delights in the macabre. The word "ghoul" has also been used to describe cannibals such as Jeffrey Dahmer. The term "ghoul" may also be used as slang, particularly in Ireland, to describe a person who acts in an odd and/or humorous manner.

The star Algol takes its name from this creature.