The Marvel Universe is a fictional shared universe where the stories in most American comic book titles and other media published by Marvel Comics take place. Super-teams such as the Avengers, the X-Men, the Fantastic Four, the Guardians of the Galaxy, and many Marvel superheroes live in this universe, including characters such as Spider-Man, Captain America, Iron Man, Thor, the Hulk, Ant-Man, the Wasp, Wolverine, Black Panther, Doctor Strange, Daredevil, and Captain Marvel, Blade, Black Widow, Hawkeye, among numerous others.

The Marvel Universe is further depicted as existing within a "multiverse" consisting of thousands of separate universes, all of which are the creations of Marvel Comics and all of which are, in a sense, "Marvel universes". In this context, "Marvel Universe" is taken to refer to the mainstream Marvel continuity, which is known as Earth-616 or currently as Prime Earth.

Founded in 1939 by Martin Goodman under the name Timely Publications, the company began by publishing a mix of superhero, crime, horror, and science fiction comics. However, it wasn't until the early 1960s that Marvel Comics truly came into its own, ushering in what would be known as the "Marvel Age of Comics." Spearheaded by visionaries like Stan Lee, Jack Kirby, Steve Ditko, and others, Marvel revolutionized the comic book landscape by creating flawed, relatable superheroes with real-world issues.