Princess Valeria is the child princess of Ingary, daughter of King of Ingary and niece to Turnip Head.

She appears briefly in the book Howl's Moving Castle as an infant, but has a much more prominent roll in Castle in the Air, where she is one of the princesses kidnapped by the djinn Hasruel. While she is originally guarded by Wizard Suliman's magic, his spells are weakened when he transforms Midnight back into her human form, allowing Hasruel to kidnap Valeria. She is critical to the princesses' escape plan, throwing a tantrum to distract the djinn while Abdullah, the soldier, and the princesses overtake him.