The film tells the story of a young girl who is cursed by a witch and turns into an old woman, and who seeks the help of a wizard named Howl to break the curse and return to her original form.

Sophie (Emily Mortimer) has an uneventful life at her late father's hat shop, but all that changes when she befriends wizard Howl (Christian Bale), who lives in a magical flying castle.

However, the evil Witch of Waste (Lauren Bacall) takes issue with their budding relationship and casts a spell on young Sophie, which ages her prematurely. Now Howl must use all his magical talents to battle the jealous hag and return Sophie to her former youth and beauty.