Fantasio is a fictional character from the Spirou et Fantasio comic strip.

Fantasio may also refer to:

• Fantasio (magician)
• Fantasio (opera), opera composed by Jacques Offenbach
• Fantasio (Smyth), opera composed by Ethel Smyth
• Fantasio, play by Alfred de Musset
• Fantasio Piccoli (1917–1981), Italian stage director

• Fantasia (disambiguation)
• Fantasy (disambiguation)
• Phantasia (disambiguation)