Josh Keaton as Steve Rogers / Captain America: The leader of a faction of Avengers against regulation and a World War II veteran was enhanced to the peak of human physicality and frozen in suspended animation, before waking up in the modern world.

Don Cheadle as James "Rhodey" Rhodes / Iron Man: The co-leader of a faction of Avengers in support of regulation and the former co-CEO of Stark Industries and a former officer in the U.S. Air Force. In the fanfiction, Rhodes and Potts have paused their relationship to re-evaluate it.

Beth Hoyt as Pepper Potts / Iron Woman: The co-leader of a faction of Avengers in support of regulation and the former co-CEO of Stark Industries and Tony Stark's former assistant. In the fanfiction, Potts and Rhodes have paused their relationship to re-evaluate it.

Lake Bell as Natasha Romanoff / Black Widow: An Avenger allied with Rhodes and Potts and a former S.H.I.E.L.D. and KGB spy.

Sebastian Stan as Bucky Barnes / Winter Soldier: A physically enhanced brainwashed assassin allied with Rogers and his childhood best friend and a World War II veteran thought killed in action. Stan reprises his role from previous MCU media.

Anthony Mackie as Sam Wilson / Falcon: An Avenger allied with Rogers and a former pararescueman trained by the military in aerial combat using a specially designed wing pack.

Jon Favreau as Happy Hogan / War Machine: An officer in the US Air Force and Tony Stark's former chauffeur and bodyguard.

Jeremy Renner as Clint Barton / Hawkeye: A master archer allied with Rogers and retired Avenger and former S.H.I.E.L.D. agent.

Chadwick Boseman as T'Challa / Black Panther: The prince of the African nation of Wakanda allied with Rhodes and Potts, who gains enhanced strength and speed by ingesting the Heart-Shaped Herb. Boseman reprises his role from previous MCU media.

Paul Bettany as Vision: An android and Avenger allied with Rhodes and Potts who was created using the artificial intelligence J.A.R.V.I.S., Ultron, and the Mind Stone.

Elizabeth Olsen as Wanda Maximoff: An Avenger allied with Rogers who can engage in hypnosis and telekinesis.

Paul Rudd as Scott Lang / Ant-Man: A former petty criminal allied with Rogers who acquired a suit that allows him to shrink or grow in scale while also increasing in strength. Rudd reprises his role from previous MCU media.

Emily VanCamp as Sharon Carter / Agent 13: A former agent of S.H.I.E.L.D. and Peggy Carter's niece who now works for the CIA and supports Rogers. VanCamp reprises her role from previous MCU media.

Marisa Tomei as May Parker: Peter's aunt. Tomei reprises her role from previous MCU media.

Hudson Thames as Peter Parker / Spider-Man: A teenager allied with Rhodes and Potts who received spider-like abilities after being bitten by a radioactive spider.

Frank Grillo as Brock Rumlow / Crossbones: The former commander of S.H.I.E.L.D.'s counter-terrorism S.T.R.I.K.E. team who was revealed to be an agent of Hydra. Grillo reprises his role from previous MCU media.

Martin Freeman as Everett K. Ross: A member of the CIA's Joint Counter Terrorism Center and Sharon's boss. Freeman reprises his role from previous MCU media.

Mike McGill as Thaddeus Ross: The United States Secretary of State and a former U.S. Army general.

Daniel Brühl as Helmut Zemo: A Sokovian colonel-turned-terrorist who is obsessed with defeating the Avengers. Brühl reprises his role from previous MCU media.

Mark Wingert as Tony Stark: Rhodes' best friend and Potts' former boss, who was killed by the Ten Rings.

Kerry Condon as F.R.I.D.A.Y.: Rhodes and Potts' artificial intelligence, who powers their suits.

John Kani as T'Chaka: T'Challa's father and the king of Wakanda. Kani reprises his role from previous MCU media.

Gene Farber as Vasily Karpov: Barnes' Hydra handler and a former Soviet colonel, who Zemo kills. Faber r Farber reprises his role from Captain America: Civil War (2016).

Florence Kasumba as Ayo: A member of T'Challa's Dora Milaje. Kasumba reprises her role from previous MCU media.

Alfre Woodard as Miriam Sharpe: The mother of an American citizen killed in Sokovia. Woodard reprises her role from Captain America: Civil War (2016).

Jim Rash as MIT staff member: An employee at MIT. Rash reprises his role from previous MCU media.

Stan Lee as himself: A FedEx delivery man who delivers a package to Rhodes and Potts. He also voices the Watcher Informant, a Watcher who tells the events on Earth.

Theo Brossaurd: A psychiatrist who Zemo murdered.

Chiwetel Eljolfor as Karl Mordo: A former Master of the Mystic Arts, who has vowed to rid the world of sorcerers. Eljolfor reprises his role from previous MCU media.

Benjamin Bratt as Jonathan Pangborn: A paraplegic and former Master of the Mystic Arts, who Mordo attacks. Bratt reprises his role from Doctor Strange (2016).

Benedict Cumberbatch as Dr. Stephen Strange / Doctor Strange: A Master of the Mystic Arts and Sorcerer Supreme and former neurosurgeon, who was led to a mystical form of healing via the Mystic Arts. Cumberbatch reprises his role from previous MCU media.

Chris Hemsworth as Thor: An Avenger and crown prince of Asgard, based on the Norse mythological deity of the same name.

Kraglin Obfonteri: A member of the Ravagers, who dons Yondu's Yaka Arrow and controls fin.

Fred Tatascoire as Drax: A member of the Guardians of the Galaxy seeking vengeance against the Mad Titan Thanos for killing his family.

Sylvester Stallone as Stakar Ogord: The leader of the Ravagers. Stallone reprises his role from previous MCU media.

Michael Rosenbaum as Martinex T'Naga: A member of the Ravagers. Rosenbaum reprises his role from previous MCU media.

Ving Rhames as Charlie-27: A member of the Ravagers. Rhames reprises his role from Guardians of the Galaxy Vol. 2 (2017).

Michelle Yeoh as Aleta Ogord: Stallone's wife and a member of the Ravagers. Yeah reprises her role from Guardians of the Galaxy Vol. 2 (2017).

Miley Cyrus as Mainframe: An robotic member of the Ravagers. Cyrus reprises her role from Guardians of the Galaxy Vol. 2 (2017).

Krugarr: A non-speaking member of the Ravagers.

Elizabeth Debicki as Ayesha: The leader of the Sovereign. Debicki reprises her role from previous MCU media.

Brian T. Delaney as Peter Quill / Star-Lord: The half-human half-Celestial leader of the Guardians of the Galaxy, who was abducted from Earth by the space pirate crew the Ravagers as a child in 1988.

Vin Diesel as Teen Groot: An tree-like humanoid and member of the Guardians of the Galaxy. Diesel reprises his role from previous MCU media.