John Fitzgerald is the main antagonist of the 2010 action comedy film Knight and Day.
He is portrayed by Peter Sarsgaard.
John Fitzgerald is a CIA agent who has been the partner of Roy Miller. During the mission to protect Simon Feck, a young and brilliant inventor who has created a perpetual energy battery called the Zephyr, Fitzgerald betrayed Roy and tried to seize the Zephyr. However, Roy and Simon managed to escape, but Fitzgerald fooled his CIA superiors by telling them that Roy is the traitor.
After detecting Roy in an airport, Fitzgerald sends some of his men to catch him. Roy secretly hide the Zephyr on a civilian named June Havens, which makes Fitzgerald believe that she is working with him so he settles her on the same plane as his men and Roy. Roy manages to kill all the men and June returns to her home, but the following day Fitzgerald comes to pick her up along with his men and tells her lies about Roy. He orders to his men to put her "safe" (meaning to kill her), but Roy arrives and saves her.
Long after, Fitzgerald and the CIA finally contact June, who believes that Roy is indeed a traitor, and convince her to lead them to lead them to him and Simon. The latter is captured, while Roy escapes but he is pursued and apparently killed. Later, Fitzgerald transports Simon along with another CIA agent, but he decides to kill the agent and to sell Simon.
A few days later, Fitzgerald deals with a crime lord named Antonio Quintana, who is interested by the Zephyr and wants to buy Simon. However, Roy, who is actually alive, and June, who made herself captured by Quintana, manage to kill all Quintana's men then Quintana himself, but Fitzgerald uses Simon as a hostage to oblige Roy to give him the Zephyr. Roy accepts, however Fitzgerald then shoots at Simon but Roy interpose and is severly wounded. Afterwards, Fitzgerald goes away aboard of his plane, however Simon reveals that the Zephyr is unstable, and it is seen exploding soon after, killing Fitzgerald.