The leader and benefactor of the Avengers who is a self-described genius, billionaire, playboy, and philanthropist with electromechanical suits of armor of his own making.

A fugitive superhero and leader of a faction of Avengers. A World War II veteran, he was enhanced to the peak of human physicality by an experimental serum and frozen in suspended animation before waking up in the modern world. Although the film was beyond Evans' initial six-film contract with Marvel which would have ended with Avengers: Infinity War, Evans agreed to appear in the film "because it made sense. It's going to wrap everything up."

An Avenger and a genius scientist who, because of exposure to gamma radiation, transforms into a monster when enraged or agitated. The character concludes a story arc that was established in Thor: Ragnarok and Avengers: Infinity War.

The shape-shifting leader of the Skrull invasion of Earth, who is working undercover within S.H.I.E.L.D. as Fury's boss. Mendelsohn described Talos's human persona as "buttoned up" compared to his "more laid back" Skrull persona. Mendelsohn differentiated between the two by using an American accent inspired by politician Donald Rumsfeld for the human disguise, and his native Australian accent for Talos; the latter was chosen, after a "lengthy discussion", due to what Mendelsohn called an "earthy correctness". The makeup and prosthetics necessary to portray Talos took "a couple of hours" to apply. Executive producer Johnathan Schwartz added that "it's sort of fun to show off both the Skrull's powers and Ben's range as an actor because he's very different in all of those parts."

An Avenger and the king of Asgard, based on the Norse mythological deity of the same name. Thor now wields a mystical axe known as Stormbreaker, after the destruction of his hammer Mjolnir in Thor: Ragnarok.

A highly trained spy, a member of Rogers' faction of Avengers, and a former agent of S.H.I.E.L.D.

A master archer, former Avenger, and agent of S.H.I.E.L.D.Barton has a new outfit in the film, visually similar to that of Ronin from the comics.

A former officer in the U.S. Air Force and Avenger who operates the War Machine armor.

A former petty criminal who acquired a suit that allows him to shrink or grow in scale and increase in strength.

An ex-U.S. Air Force pilot whose DNA was altered during an accident, which imbues her with the powers of superhuman strength, energy projection and flight. Screenwriter Christopher Markus stated that Danvers' powers are on a scale that has not previously existed in the MCU and likened her personality to Rogers', "which is sort of a person who's right and knows they're right and doesn't really want to hear it when you tell them they're wrong".

An intergalactic despot from Titan who collected the six Infinity Stones to inflict his will on all of reality. Joe Russo said that after the events of Avengers: Infinity War, "[Thanos has] succeeded in the thing he has set out to do. He's done. He did it. He's retired." In addition to providing the voice for the character, Brolin performed motion capture on set.

Stark's fiancée and the CEO of Stark Industries, who will wear a powered exosuit of armor in the film. This will be Paltrow's final major appearance as Potts in the MCU.

A member of the Guardians of the Galaxy who is a genetically-engineered raccoon-based bounty hunter and mercenary, and is a master of weapons and battle tactics. Sean Gunn was again the stand-in for Rocket during filming, with his acting and expressions serving as motion reference for the character.