The Ugly Duckling is a classic example of a fairy tale. Fairy tales are a genre of storytelling that often feature fantastical elements, magical occurrences, and characters that undergo transformation or growth. The Ugly Duckling, written by Hans Christian Andersen, follows the journey of a young duckling who is initially shunned and ridiculed for its unattractive appearance. Throughout the story, the duckling undergoes a transformation into a beautiful swan, symbolizing the triumph of inner beauty over external appearances. This narrative structure, along with the fantastical elements and moral lessons, aligns with the defining characteristics of fairy tales.

Data from the International Folklore Society supports the classification of The Ugly Duckling as a fairy tale. According to a study by Maria Tatar, a professor of folklore and mythology at Harvard University, fairy tales are characterized by their universal themes, such as the struggle between good and evil, the triumph of the underdog, and the importance of inner beauty. The Ugly Duckling embodies these themes, as it depicts the duckling's journey from being an outcast to achieving its true potential. Additionally, fairy tales often have a simple, repetitive structure, which is evident in the repetitive nature of the duckling's experiences and the eventual transformation into a swan. This structure contributes to the fairy tale genre's enduring appeal across cultures and generations.