Mission: Impossible IV is the title to the fourth film in the Mission: Impossible film series.
- Tom Cruise as Ethan Hunt: Now married to Julia, Ethan still continues to work in the Impossible Mission Force. On a mission raiding a cargo ship under the employ of the terrorist organization the Black Arms, Ethan surprisingly finds a sedated Jim Phelps. Saving Phelps, Ethan gets him and himself out of the ship and takes him to IMF headquarters. Jim tells everyone about what happened to him. Ethan and Jim regroup their old teams to work together to take down the Black Arms.
- Peter Graves as Jim Phelps: Years earlier Jim was captured by the terrorist organization known as the Black Arms. He was replaced with a Black Arms agent named Roderick Quinn who used reconstructive surgery to get Jim's appearance. While Jim was being transported to America sedated Ethan Hunt saves him and brings him back to IMF headquarters. Jim explains what happened to him. With Ethan Hunt they gather their old teams to take down the Black Arms.
- Laurence Fishburne as Theodore Brassel: Theodore is the head of the Impossible Mission Force and old associate of Jim Phelps. Theodore sends Ethan Hunt on a mission to raid a cargo ship being used by the terrorist organization known as the Black Arms where he rescues Jim Phelps. Ethan brings Phelps back to IMF Headquarters where Jim tells Theodore about what had happened to him. Theodore assigns Ethan and Jim to work together to take down the Black Arms.
- Brad Pitt as John Phelps: John Phelps is the son of the famous IMF agent Jim Phelps. John has become one of the IMF's best agents rivaling Ethan Hunt. The two are competitive with each other. Eventually he is reunited with his father to help Ethan and him take down the terrorist organization known as the Black Arms. John accepts the mission.
- Leonard Nimoy as Paris: It has been several years since Paris has been with the Impossible Mission Force. He became a full time actor. When Jim Phelps was rescued by Ethan Hunt, Jim asked his old friend to help him with his mission to take down the Black Arms. At first Paris refuses, but he then decides to join.
- Morgan Freeman as Barney Collier: Barney has worked outside of the Impossible Mission Force for years running Collier Electronics. When Jim Phelps was rescued by Ethan Hunt Jim asked Barney to help him on one final mission to take down the Black Arms. Barney accepted.
- Peter Lupus as Willy Armitage: After leaving the IMF Willy became a security guard at a laboratory for a science lab, and eventually became the head of security. The newly rescued Jim Phelps offered Willy to aid him in one last mission against the Black Arms which he accepted.
- Lynda Day George as Lisa Casey: After leaving the IMF Lisa married a rich industrialist named Arnold Canton, who eventually died leaving her a widow. When Jim offers her to help him take down the Black Arms there is tension between the two of them. It is eventually revealed that she is the mother of John Phelps.
- Ving Rhames as Luther Stickell: Luther is an old friend of Ethan Hunt and has helped him on several missions. Ethan recruits his old friend to help him take down the Black Arms alongside Jim Phelps and his old team.
- Maggie Q as Zhen Lei: A member of Ethan Hunt's team that Ethan recruits to help bring down the Black Arms.
- Jonathan Rhys-Meyers as Declan Gormley: A member of Ethan Hunt's team that Ethan recruits to help bring down the Black Arms.
- Phil Morris as Grant Collier: Barney's son and vice president of Collier Electronics.
- Wes Bently as Malachi Knight: Malachi Knight is the leader of the American branch of the terrorist organization known as the Black Arms. When Jim Phelps is liberated by Ethan Hunt he is blamed by his superior for what had happened and was ordered to get him back or kill him. Malachi complies with this and sends his best assassins after him.
- Zachary Quinto as Nicolas Archer: Nicolas Archer is the right hand man of Malachi Knight, the leader of the American branch of the terrorist organization named the Black Arms. He is very proficient with firearms with perfect aim. He was on security detail on the cargo ship transporting Jim Phelps to America. While Ethan Hunt was raiding it the two battled until Nicolas was forced to escape by jumping out through a window. Afterwards Nicolas is sent by his boss Malachi Knight to capture or kill Jim Phelps.
- Jeremy Irons as Wyatt Raines: Wyatt Raines is a politician that is a member of the department of defense, and secret ally of the Black Arms, supplying them information about the U.S. government.
- Jet Li as Shang Wan: Shang Wan is an assassin that works for the Black Arms. He tries to kill Jim Phelps and Ethan Hunt at the Empire Hotel in New York.
- Christopher Lee as General Mikhail Zarkoff: The leader of the Black Arms.
- Tyler Mane as Fritz: One of Zarkoff's bodyguards.
- Kevin Nash as Hans: Zarkoff's other bodyguard.
A large ship is approaching the docks of Manhattan. A young man with sleeked back black hair is watching from the bridge overseeing everything about the ship.