Mad Dog, in comics, may refer to:

• Mad Dog (DC Comics), a DC Comics supervillain
• Mad Dog, a number of Marvel Comics characters:
  • Mad Dog (Marvel Comics), a Marvel/Timely Comics supervillain
  • Mad Dog Rassitano, a Marvel Comics character and fictional SWAT member
  • Mad Dog #336, an alias used by Peter Parker^[1]
  • Mad Dog #736, an alias used by Captain Zero^[1][2]
  • Mad Dog #2020, an alias used by Brainstorm^[3]
  • "Mad Dog" Martin, a character who appeared in Combat Kelly and his Deadly Dozen^[4]
  • "Mad Dog", a Marvel comics title based on the fictional comic of the same name in the sitcom Bob.