Contagion is a story arc that ran through the various Batman comic book series. It concerns the outbreak of a lethal disease (The Clench) in Gotham City, and Batman's attempts to combat it. The events of this story led into Batman: Legacy and Batman: Cataclysm, which itself leads into Batman: No Man's Land.

Much of the plot centers around a gated community in the middle of Gotham City, whose wealthy residents believe they can protect themselves from the plague by sealing themselves inside, only to discover that one of their number is the plague's first carrier. In this the story parallels the plot of Edgar Allan Poe's short story The Masque of the Red Death, which one of the community's dying residents mentions.