In fairy tales, a fairy godmother is a fairy with magical powers who acts as a mentor or parent to someone, in the role that an actual godparent was expected to play in many societies. In Perrault's Cinderella, he concludes the tale with the cynical moral that no personal advantages will suffice without proper connections. The fairy godmother is a special case of the donor.
In the tales of précieuses and later successors, the fairy godmother acts in a manner atypical of fairies in actual folklore belief; they are preoccupied with the character and fortunes of their human protegees, whereas fairies in folklore had their own interests.
Typically, the fairy godmother's protégé is a prince or princess and the hero of the story, and the godparent uses her magic to help or otherwise support them. The most well-known example is probably the fairy godmother in Charles Perrault's Cinderella. Multiple fairy godmothers appear in Sleeping Beauty, in both Charles Perrault's and the Grimm Brothers's variants, including one evil, offended one. The popularity of these versions of these tales led to this being widely regarded as a common fairy-tale motif, although they are less common in other tales.
Indeed, the fairy godmothers were added to Sleeping Beauty by Perrault; no such figures appeared in his source, "Sole, Luna, e Talia" by Giambattista Basile. In the Grimm Brothers' variant of Cinderella, Aschenputtel is aided not by her fairy godmother but by her dead mother. A great variety of other figures may also take this place.
Madame d'Aulnoy created a fairy godmother for the evil stepsister in her fairy tale The Blue Bird; in this position, the fairy godmother's attempts to bring about the marriage of her goddaughter and the hero are evil attempts to impede his marriage with the heroine. Likewise, in her The White Doe, the fairy godmother helps the evil princess get revenge on the heroine. In Finette Cendron, the fairy godmother is the heroine's, but after helping her in the early portion of the tale, she is offended when Finette Cendron does not take her advice, and Finette must work through the second part with little assistance from her.
In William Makepeace Thackeray's The Rose and the Ring, the fairy Blackstick concludes that her gifts have not done her godchildren good; in particular, she has given two of her goddaughters the title ring and the title rose, which have the power to make whoever owns them beautiful, which have ruined the character of those goddaughters; with the next prince and princess, she gives them "a little misfortune", which proves the best gift, as their difficulties form their characters.
In C. S. Lewis's The Magician's Nephew, when Uncle Andrew explains how he made the magical rings from dust left to him by his godmother, he points out that she may have had fairy blood, and so he might have been the last man to have a fairy godmother.
In Shrek 2, the fairy godmother turns out to be a conniving, crooked businesswoman (with a personality rather like that of the Stepmother in Cinderella), who is quite willing to resort to blackmail and/or murder to further her own interests.
The Discworld novel Witches Abroad also features a plotting fairy godmother, Lady Lilith de Tempscire, who uses the power of stories to control the city of Genua. During the book Magrat Garlick also takes on the role, but throws away the magic wand at the end.
In "The Dresden Files" novels (primarily "Grave Peril" and "Summer Knight"), the main character, a modern wizard named Harry Dresden is revealed to have a faerie godmother by the name of Leanansidhe who enjoys ensnaring Harry in one-sided deals.
The first King's Quest game features a fairy godmother of the main character Graham who can grant him invincibility.