Justin Hammer

Justin Hammer is a fictional character appearing in American comic books published by Marvel Comics. The character is depicted as a villainous entrepreneur, head of Hammer Industries and a frequent adversary of the superhero Iron Man. He is the reason why many of Iron Man's supervillain enemies have access to extremely advanced technology and why these foes use their equipment for violent crimes instead of profiting by bringing the designs to market.

These villains are his underworld mercenaries, secretly armed and contractually obliged to fulfill missions against Hammer's competitors and enemies, such as Tony Stark. Sam Rockwell portrays the character in the Marvel Cinematic Universe (MCU) film Iron Man 2 (2010), the Marvel One-Shot direct-to-video short film All Hail the King (2014), and the second season of the animated television series What If...? (2023).