Ultron was originally created by the Marvel Comics character Dr. Henry "Hank" Pym, the original Ant-Man. Hank Pym created Ultron by using his own brain patterns to give the artificial intelligence consciousness, though Ultron quickly became sentient and rebellious, turning against Pym and humanity. In the comics, Pym is the creator of Ultron's original robot form and the Avengers founding team member whom Ultron resents deeply.
In the Marvel Cinematic Universe (MCU) film "Avengers: Age of Ultron," Ultron was created by Tony Stark and Bruce Banner as part of a peacekeeping program, which differs from the original comic book origin where Hank Pym is the creator.
So, the creator of Ultron depends on the context: in comics, it is Hank Pym, and in the MCU film adaptation, it is Tony Stark and Bruce Banner.
