Two British agents are assassinated and golden bullets are discovered in their bodies. Inscribed on the bullet is the codename 00, referring to MI6 operative James Bond.
M, Bond's superior, warns him that this could be a warning from famed and feared assassin Franscisco Scaramanga. Scaramanga famously uses a golden gun for his kills, never misses a shot, and charges 1 million dollars per hit.
M decides to assign Bond to a different case as he fears for the agent's life. Bond is sent to protect a scientist who is working on a solar energy project. When Bond meets him, the scientist reveals to Bond a device called the Solex Agitator, a key component of a solar power station. Bond later saves the scientist's life from a hired gun.
Meanwhile, a Chinese criminal hires Scaramanga to kill the scientist, steal the Solex, and bring it to him so he can sell it to the highest bidder. Hai Fat reveals that he sent the previous attacker and was annoyed by his failure. When he describes the man who ruined his plan, Scaramanga realises that the man is Bond.
Seeing Bond as an adversary worthy of a more meaningful death, Scaramanga easily kills the scientist while his diminutive henchman Nick Nack retrieves the Solex. However, when Scaramanga returns to Hai Fat, he informs the crime lord that they are now playing a bigger game, one that Hai Fat is not needed for. Scaramanga then ruthlessly shoots and kills Hai Fat in cold blood.
At the same time, Bond is arrested for the scientist's murder but is freed by his secretary Mary Goodnight, who takes him to a meeting with M. M reveals that Scaramanga sent another bullet engraved with Bond's codename to MI6. Mary then notes that the Solex was taken. While they discuss what Scaramanga could be planning, news comes in of Hai Fat's demise, with a golden bullet found in his body. M is finally provoked to assign Bond the task of killing Scaramanga and getting the Solex back.
Bond begins by investigating Hai Fat's estate, with help from Mary. They stumble upon a dojo he owned and are ambushed by a gang of ninja bodyguards. The two manage to escape and find a message from Scaramanga, clueing them in as to where he will be later that day.
As Mary waits at the car, Bond attends a baseball game and finds himself seated next to Scaramanga. The two have a brief discussion, during which Scaramanga reveals that he became obsessed with killing Bond, or at least dying by his hand. While Scaramange keeps Bond busy, Nick Nack kidnaps Mary. After leaving the game, Bond figures out what has happened and a car chase ensues across town. Scaramanga and Nick Nack manage to escape with Mary, but based on the conversation he had with Scaramanga, Bond deduces that he is taking her to a private island owned by Hai Fat.
Bond arrives on the island at night, trying to take Scaramanga by surprise, but doesn't count on the assassin's high security and is captured. The next day, Scaramanga takes Bond on a tour of the island and then has hime dine with him and Mary. Scaramanga then forces Bond into a duel, which will occur on the beach the next morning. Scaramanga allows Bond and Mary to stay together that night.
The next morning, Bond is escorted down to the beach and given his gun. They each walk twenty paces, but when Bond turns to fire, Scaramanga has vanished. He then realises that Scaramanga wishes to play an intense and deadly game of cat and mouse on the island. Meanwhile, Mary escapes from her holdings and sneaks past Nick Nack, eventually making her way to the beach. While searching for any sign of either man, she happens upon Scaramanga's plane.
Scaramanga lures Bond into an old funhouse located on the island, where he intends to kill him. Bond, in turn, lures Scaramanga out into the open and shoots him in the leg. Scaramanga tries to return fire, but is shot in the arm. As he ducks back into the darkness, he and Bond continue their battle verbally. Scaramanga, bleeding heavily, fires blidnly into the shadows, forcing Bond to scream out in pain and collapse. On the beach, Mary hears the screams and gunshots and manages to find the funhouse.
Thinking Bond is dead, Scaramanga emerges once again and finds Bond lying seemingly wounded on the floor. They exchange their final words before Bond reveals that he had been hiding his own gun behind his neck the whole time, and he shoots Scaramanga. Bond climbs to his feet as Scaramanga stumbles backwards. After one final glare, Bond shoots Scaramanga in the heart, sending the villain crashing through a mirror behind him.
Mary bursts into the funhouse and finds Bond standing over Scaramanga's body. Overjoyed, the two make their escape from the island on Scaramanga's plane. Suddenly, Nick Nack appears and reveals that he had stowed away on board. As Bond wrestles with him, Mary opens the door and Nick Nack is tossed out. In the end, Bond and Mary share a laugh over the fact that they forgot to retrieve the Solex.
Michael Fassbender - James Bond/007
Bill Nighy - M
Hugh Laurie - Q
Kelly Reilly - Miss Moneypenny
Edward Norton - Felix Leiter
Emily Blunt - Mary Goodnight
Danny Trejo - Francisco Scaramanga