The White Hound of the Mountain (Irish: Cú Bán an tSléiḃe) is an Irish folktale collected in the early 20th century and published in academic journal Béaloideas. It is related to the international cycle of the Animal as Bridegroom or The Search for the Lost Husband, wherein a human maiden marries a man under an animal curse, loses him and has to search for him.
 The tale was originally collectd in Belmullet, County Mayo, in 1903, from an informant called Antoine Sirin (Searns).
 A king has a magical wishing chair. His three daughters, the princesses, wish to see for themselves its mystical powers. Each girl sits on the chair and wishes for a husband: the first for the king of the Eastern World, the second for the King of the Western World and the youngest for the titular "White Hound of the Mountain". As they predicted, each of their husbands appear to claim them. The third suitor, however, is not met with the same reception as the others. After three attempts, the White Hound takes the third princess as his intended and goes with her to their new home. The White Hound reveals himself to be a man by night and a hound by day. They live together and she bears him three children. After each birth, the children are taken from them by a mysterious lady. The third princess visits her family and, hounded by her relatives, tells everything about her married life. The White Hound becomes a crow and disappears, and his wife goes after him. The princess visits three houses and obtains a pair of scissors, a comb and a reel for winding yarn. At last she reaches the castle of the Queen of the Black Cloak, the witch who enchanted her husband, and bribes her with the golden objects she received.
 The tale is classified in the international Aarne-Thompson-Uther Index as type ATU 425A, "The Animal as Bridegroom". in this tale type, the heroine is a human maiden who marries a prince that is cursed to become an animal of some sort. She betrays his trust and he disappears, prompting a quest for him. According to Irish folklorist Dáithí Ó hÓgáin, type 425 is known in Ireland as Cu Ban an tSléibhe ("The White Hound of the Mountain"): the heroine marries a prince cursed to be a hound by day, burns his dogskin and finds him under the power of a witch, with whom she trades three wonderful and magical objects (a comb, scissors and a needle) for three nights with him.
 According to Hans-Jörg Uther, the main feature of tale type ATU 425A is "bribing the false bride for three nights with the husband". In fact, when he developed his revision of Aarne-Thompson's system, Uther remarked that an "essential" trait of the tale type ATU 425A was the "wife's quest and gifts" and "nights bought".
 According to Jan-Öjvind Swahn [sv]'s study on some 1,100 variants of Cupid and Psyche and related types, the motif of the "wishing chair" appears in Celtic, Irish and British variants. In the same study, he concluded that the dog as the animal husband appears "confined to the Germanic and Celtic areas".
 The motif of the separation of the heroine from her children is located by scholarship across Celtic and Germanic speaking areas. According to scholar Gerard Murphy, in Irish variants, the children are taken by a "Hand-down-the-chimney", a motif that also appears in the Fenian Cycle.
 An Irish language variant titled Cú Bán an t-Sléibhe ("The White Hound of the Mountain"; IPA:[kuːbˠaːnˠənˠˈtʲlʲeːvʲə]) was published in the academic journal Zeitschrift für celtische Philologie. In this tale, the king's three daughters open a door to a room their father forbid them to enter, and sit on a chair. All three express their wishes for a husband, and the youngest says she will marry "The White Hound of the Mountain", without knowing if he exists or not. They marry and she gives birth to three children of wondrous aspect, who are taken from her by unknown forces. At the end of the tale, the heroine uses golden items she was given on her way to her husband's location to bribe the witch (named Cúl-Carrach) and her daughter (named Maol-Charrach) for three nights with him. The witch who cursed him can only be defeated by breaking the egg with her life in it. The tale was translated into German as Der Weisse Hund vom Gebirge ("The White Hound of the Mountain"). Reidar Christiansen identified this variant as hailing from Galway, and also classified the tale as types 425 and 302.
 In another homonymous variant titled Cú Bán a' tSléiḃe ("The White Hound of the Mountain"), a king has a magical wishing chair (cathaoir a' tsóláis). Each of his three daughters wish for a husband: the elder for a husband more beautiful than the sun, the middle one for one more beautiful than the moon, and the third for the White Hound. In time, all three bridegrooms arrive to get their respective brides, the White Hound taking his through a secret forest path. In their castle, the White Hound  asks his wife which form she prefers him to be, and she answers that as a man by night. Some time later, the princess is pregnant with their first child (a son, White Hound prophecises), and is taken to her family's castle to give birth, but with instructions to leave the child outside the gate for the White Hound to take him. The same happens to their second child, but, with the third pregnancy, the White Hound alerts his wife not to return home, since her new step-mother will force her to disclose the princess's married life. Despite the warnings, the princess goes to her father's castle and leaves her third son outside. Inside, the princess's stepmother tortures her with an iron poker, and, to avoid further harm to herself, the princess gives in and tells everything to her perfidious step-mother. The princess awaits for her husband to come, but he does not, so she walks by herself to the White Hound's castle, finding nothing but ruins. She notices three sods and picks them up. When she tosses one, her husband appears with their sons, and flees soon after. The princess runs after him, until she stops to rest by an old woman's hut. Before the princess leaves, the old woman tells her that her family stopped there - her proof a half-bitten sandwich -, and gives her a pair of magic scissors. Her pursuit continues with two next stops, where she gets a comb and a box, until she reaches her father-in-law's castle. For a year and a day, the White Hound (back to human form), lives with his father, and announces he shall marry one that can wash his bloodied shirt. The princess washes it, but the hen-wife's daughter takes the credit for it, and is set to marry the human White Hound. The princess uses the old women's gifts (a scissors that turn cloth to silk, a comb that turns hair golden and the box that sping yarn) to bribe the false bride for three nights with the White Hound. For the first two nights, she cannot wake him up, due to him drinking a sleeping potion, until the third day, where he wakes up and recognizes her.
 In an homonymous tale collected by Séamus Ó Duilearga in 1962 with the title Cú bhán an tSléibhe ("The White Hound of the Mountain"), a widowed king has three daughters. While he is away, he locks up a magical chair inside a room, which grants wishes to anyone who sits on it. One day, his three daughter decide to test it by wishing for husbands: the elder asks for the most honored man in the world to come that very night to spouse her, and the middle one for the second most honored man. The youngest does not want to sit on the chair, but, persuaded by her elder sisters, sits on it and wishes for the Cú Bhán an TSléibhe ("White Hound of the Mountain") to come and marry her. The next day, the elders' wishes come true, which means that the youngest's will come too. The White Hound of the Mountain appears to claim his bride, but the king tries to trick him by sending a servant's daughter. Twice he falls for it, but realizes the deception and comes back for his true bride the third time. When they arrive at their new home, the White Hound asks his wife which she prefers: that he is a hound by morning or man at night, or the opposite. She chooses the second option, and the White Hound remains an animal by day and human by night. Time passes, and she becomes pregnant, but wishes to giev birth at her father's house. The White Hound agrees to her return, but warns her not to cry if anything happens to their children. The princess goes back home and, in three consecutive pregnancies, gives birth to her children, but each time a black figure comes down the chimney and takes the child from her. The princess betrays his trust, he vanishes, and she has to search for him in Tir na Hóige. During her journey, she passes by the houses of three old ladies who are also taking care of her children, and is given a magical object in each. Finally, she reaches Tír na Hóige, where she lives in a pigpen. The lady of the castle, Calleach Bharrach (Old Woman Bharrach) and her daughter Iníon Mhaol Charrach see the wonderful gifts of the princess (a magical pair of scissors, a magical comb and a magical ring), and wish to buy them. The princess agrees to a deal: each time, she offers a magical item for one night with the sleeping White Hound of the Mountain, who has remained in human form. The princess cannot wake him up on the first two nights, but manages to wake him up on the third. The White Hound wakes up and reunites with his true wife, and tells her they have to destroy the external soul of the witches, hidden in a duck's egg that is hidden in a duck, hidden in a sheep's belly, hidden in a boar.
 In his collection Popular Tales of the West Highlands, author John Francis Campbell reported in the section "Gaelic list" a Scottish Gaelic tale titled Cu ban an ’t Sleibhe, collected from an informant named Marian Gillies, from Port an long, North Uist.
 The tale was reworked by author Thomas Kiernan in his book The White Dog of the Mountain and other Irish tales.