Ultron is a fictional supervillain appearing in American comic books published by Marvel Comics. He is most recognized as a nemesis of the Avengers, and has a quasi-familial relationship with his creator Hank Pym. He was the first Marvel Comics character to wield the fictional metal alloy adamantium.
Ultron has been voiced by Tom Kane and by Jim Meskimen in several media adaptations. The character is played by James Spader in the 2015 film Avengers: Age of Ultron.