Ant-Man and the Wasp: Quantumania will be a "sci-fi" adventure set in the Quantum Realm.
The third film in the Ant-Man trilogy will be on the same scale as an Avengers movie.
Ant-Man will face off against Kang the Conqueror, a "formidable villain" and "the most powerful force in the Multiverse.
The film will take place largely in the Quantum Realm, an "incredibly complex subatomic world" with its own ecosystems and creatures.
Director Peyton Reed wants Ant-Man 3 to be seen as more than just a "palate cleanser" between Avengers movies.
Reed has indicated that Kang the Conqueror's role in the film will be different from his portrayal in the comics.
Reed has said that Kang, Loki, and Doctor Doom are "all-timers" among Marvel Comics villains.
The film will explore the Quantum Realm in greater depth than the first two Ant-Man movies.