In folklore and literature, the Fairy Queen or Queen of the Fairies is a female ruler of the fairies, sometimes but not always paired with a king. Depending on the work, she may be named or unnamed; Titania and Mab are two frequently used names. Numerous characters, goddesses or folkloric spirits worldwide have been labeled as Fairy Queens.

The Tuatha Dé Danann and Daoine Sidhe of Irish mythology had numerous local kings and queens. Oonagh, Una or Nuala was the wife of Finvarra or Fionnbharr, fairy king of western Ireland, although he frequently took other lovers. She was usually described living with Finvarra in his hill Cnoc Meadha, but was sometimes said to have a separate residence in Cnoc Sidh Una (Knockshegouna). In one story following the model of the Fairies' Midwife (Aarne-Thompson type 476), "Fionnbharr's wife" (unnamed) is thoughtlessly cursed by a human girl who must then serve as her midwife. Fionnbharr's wife attempts revenge by giving the girl a belt that will cut her in two when she puts it on, but a fairy servant warns the girl in time. Other Irish fairy queens included Clíodhna of Munster, Aibhell and Ainé.

The Arthurian character of Morgan le Fey (or Morgan of the Fairies) ruled the supernatural island of Avalon and was sometimes depicted as a fairy queen. In the Vita Merlini, she is Morgen, the chief of nine magical sister queens.

Fairy queens appear in some of the Child Ballads. A kind and helpful fairy queen features in Alison Gross (Child 35), and a terrible and deadly fairy queen is the antagonist of Tam Lin (Child 39). Tam Lin's Fairy Queen pays a tithe to Hell every seven years, and Tam Lin fears that he will be forced to serve as a human sacrifice:

An unnamed fairy queen appears in Thomas the Rhymer (Child 37), where she takes the titular character as her lover and leaves him with prophetic abilities. Although the romances and ballads associated with Thomas the Rhymer have parallels to Tam Lin, including the tithe to Hell, this fairy queen is a more benevolent figure.

In Thomas Cheyne's rebellion in January 1450, "the King of Fairies" (Regem de ffeyre) and "The Queen of Fairies" (Reginam de ffeyre) were among the aliases used by the (male) leaders.

Goodwin Wharton, a 17th-century English politician and mystic, believed that he had married a fairy queen named Penelope La Gard.

There were numerous local beliefs of fairy queens, some of whom had proper names. A charm from the Isle of Man names the fairy rulers as King Philip and Queen Bahee. One Welsh folk informant stated that the queen of the Tylwyth Teg was Gwenhidw, wife of Gwydion ab Don, and small, fleecy clouds were her sheep.