The clurichaun (/ˈkluːrɪkɔːn/) or clúrachán (from Irish: clobhair-ceann) is a mischievous fairy in Irish folklore known for his great love of drinking and a tendency to haunt breweries, pubs and wine cellars. He is related to the leprechaun and has sometimes been conflated with him as a shoemaker and a guardian of hidden treasure. This has led some folklorists to suppose that the clurichaun is merely a leprechaun on a drinking spree, while others regard them as regional variations of the same being. Like the leprechaun, the clurichaun is a solitary fairy, encountered alone rather than in groups, as distinct from the trooping fairies.

In the folktale "The Haunted Cellar", recorded by Thomas Crofton Croker in 1825, a clurichaun named Naggeneen haunts the wine cellar of an Irish lord, drinking everything in sight and playing frightening pranks on the servants. He is described as a little man measuring 6 in (150 mm)in height, with a face like a withered apple. He has twinkling eyes and a nose that is red and purple from heavy drinking. He wears a red nightcap, a short leather apron, light blue stockings, and shoes with large silver buckles. When he is discovered by the master of the house, Naggeneen talks him out of moving elsewhere by implying that he would simply move with him.

Other descriptions have him wearing red like other solitary fairies.

In another tale, "Master and Man", a young man named Billy Mac Daniel is on his way home one winter night when he is offered a glass of liquor by a clurichaun to warm himself. He takes the drink but when he refuses to pay for it he is compelled by the clurichaun to serve him for seven years and a day. Billy, however, is eventually able to break his servitude by invoking the blessing of God. In this story, the clurichaun is able to pass through keyholes to invade homes and wine cellars and can transform bog rushes into horses to be used as mounts. Clurichauns can also fly through the air on rushes similar to witches and their broomsticks.

Thomas Keightley in his Fairy Mythology (1828) presents the story of a clurichaun named Little Wildbean who was more helpful than others of his kind, but also quick to anger and violence when slighted. He haunted the wine cellar of a Quaker gentleman named Harris, and if one of the servants was negligent enough to leave the beer barrel running then Little Wildbean would wedge himself inside to stop the flow until someone came to turn it off. His dinner was left for him in the cellar, but one night the cook left him nothing but part of a herring and some cold potatoes. At midnight Wildbean dragged the cook out of her bed and all the way down the hard cellar stairs, leaving her battered and bruised so that she was bedridden for three weeks. In a common folktale motif Mr. Harris tried to rid himself of Wildbean by moving elsewhere but decided to turn back when he discovered the clurichaun had moved with him.

The folklorist Nicholas O'Kearney described the clurichaun in 1855 as follows:

The Clobhair-ceann was another being of the same class: he was a jolly, red-faced, drunken little fellow, and was ever found in the cellars of the debauchee, Bacchus-like, astride of the wine-butt with a brimful tankard in hand, drinking and singing away merrily. Any wine cellar known to be haunted by this sprite was doomed to bring its owner to speedy ruin.

Katharine Briggs stated that he was "a kind of buttery spirit, feasting himself in the cellars of drunkards or scaring dishonest servants who steal the wine."

He is also described as a trickster and practical joker, and a disturber of order and quietness in a household, making noise day and night. Despite his often troublesome nature, the clurichaun takes special care of the family to whom he has attached himself, endeavoring to protect their property and lives, provided he is not interfered with. This dual nature makes him similar to the domestic hobgoblin.

Besides his love of drinking, the clurichaun also enjoys pipe smoking, and the small disposable clay pipes known as "fairy pipes" that are often found while digging or plowing are said to belong to him. He also knows the secret of making beer from heather.

Alternate spellings include cluracan, cluracaun, cluricaun, and cluricaune.