You are really on my very last nerve. You are a mind-boggling pain in my ass.
~ John Royce to Mark Sheridan

Special Agent John Royce is the main antagonist in the 1998 film U.S. Marshals.

He is portrayed by Robert Downey Jr., who also portrays Vivian Thompson and Dr. Kozak.


Royce is a mole working within the U.S. State Department who had been selling covert secrets to China, and a trained operative named Mark Sheridan had been trying to expose the mole. Royce sets Sheridan up as the culprit behind two homicides, both of which were U.S. Diplomatic Security Service agents attempting to intercept a criminal briefcase exchange at a parking lot. Sheridan is arrested in Chicago and put on a plane to New York with other prisoners, supervised by Chief Deputy U.S. Marshal Samuel Gerard. After Sheridan prevents an assassination attempt on board the craft from one of his fellow prisoners, the plane is forced to make an emergency landing and Sheridan escapes. Royce is then sent to join Gerard and his team to search for Sheridan.

Royce and Gerard encounter Sheridan on several occasions, though Sheridan refuses to kill them and manages to escape. A couple of days later, Royce and Gerard find him at a funeral at a chapel confronting Agent Frank Barrows, who gets killed by Xian Chen, and then Royce, Gerard, and some other agents chase Sheridan all the way to a senior care facility and to the top of the building, where Royce is attacked by Sheridan. Royce tries to murder him, but Sheridan climbs out of the window and onto the roof, just as Gerard's associate Deputy Marshal Noah Newman enters the room. Royce shoots Newman, and lies to Gerard and the police force that Sheridan shot him. Upon arrival at the hospital, Newman was pronounced dead.

Gerard and Royce successfully track Sheridan yet again at a marine loading dock, where Gerard chases Sheridan and they fight. Royce appears and shoots at Sheridan, injuring him, and he is later taken into custody. At the hospital, Gerard starts to suspect that Royce is involved with the mole Sheridan was investigating after noticing a visual inconsistency on the side of his gun. Gerard goes to get some coffee and Royce tells the police officer guarding Sheridan's room to leave. Royce then enters the room and tries to murder Sheridan, revealing to him that he is the mole who set him. Gerard returns and confronts Royce, already realizing the truth, but Royce then attempts to shoot him. He finds the gun is empty thanks to Gerard having already anticipated his next move and Royce slowly reaches for his backup firearm. He aims at Gerard a second time, but Gerard fires first, killing Royce. Thereafter, Sheridan is exonerated of all charges and reunited with his girlfriend Marie Bineaux.