"Age of Ultron" (abbreviated AU) is a 10-issue limited series comic book crossover storyline published by Marvel Comics that involved the return of Ultron and his conquest of the earth.

The event was published between March and June 2013 and featured a storyline by Brian Michael Bendis. Artist Bryan Hitch provided the art for issues one through five, and Brandon Peterson for issues six through eight. Other artists who contributed to the series include Carlos Pacheco and Joe Quesada, the latter of whom drew part of the final issue.

Marvel stated that all art for the series was completed before it was solicited, ensuring deadlines were met and that there were no more than thirteen tie-ins to the four-month event. Age of Ultron is also intended to set up "Wave Two" of the Marvel NOW! event, particularly the Avengers A.I. series.[citation needed]

This story took place on two different Earths: The alternate Earth-616 that Ultron annihilated humanity was referred to as Earth-61112 and the alternate reality where Morgan le Fay took over half the world was referred to as Earth-26111.