Wonder Dog may refer to:

• Wonder Dog, the pet of Wendy and Marvin, two teenage characters of Super Friends
• Wonder Dog, musician Harry Thumann's side project, best known for the 1982 single "Ruff Mix"
• Wonder Dog (video game), a 1992 Mega CD video game by Core Design, ported in 1993 to the Amiga
• Wonder Dog (Disney short), a 1950 short animation by the Walt Disney Company
• Rex the Wonder Dog, a fictional dog in the DC Comics universe