Look up castle in the air in Wiktionary, the free dictionary.
A castle in the air is a daydream or fantasy.
Castle in the Air may refer to:
- Castle in the Air (play), a 1949 play by Alan Melville
- Castle in the Air (film), a 1952 British comedy film based on the play
- Castle in the Air (novel), a 1990 young adult fantasy novel by Diana Wynne Jones
- the Castle in the Air, in the children's book The Phantom Tollbooth, where the princesses of Rhyme and Reason are banished