Night at the Museum is a 2006 fantasy comedy film directed by Shawn Levy and written by Robert Ben Garant and Thomas Lennon. It is based on the 1993 children's book by Milan Trenc. The film stars Ben Stiller in the lead role, alongside Carla Gugino, Dick Van Dyke, Mickey Rooney, Bill Cobbs, and Robin Williams. It tells the story of a divorced father who applies for a job as a night watchman at New York City's American Museum of Natural History and subsequently discovers that the exhibits come to life at night, animated by a magical Egyptian artifact.

Night at the Museum premiered in New York City on December 17, 2006, and was released in the United States on December 22 by 20th Century Fox. The film received mixed reviews from critics and grossed $574.5 million, becoming the fifth highest-grossing film of 2006. Two live-action sequels were released: Night at the Museum: Battle of the Smithsonian in 2009, and Night at the Museum: Secret of the Tomb in 2014. An animated sequel, Night at the Museum: Kahmunrah Rises Again, was released in 2022 on Disney+.

In New York City, Larry Daley is a divorced aspiring inventor bouncing between jobs and apartments. His ex-wife Erica is sympathetic to his situation, but considers him a bad example to their ten-year-old son Nick, an elementary schooler who considers quitting ice hockey and plans to become a bond trader like Erica's fiancé Don when he grows up. This makes Larry worry that Nick admires Don instead of him, especially after Nick decides to invite Don to Career Day at his school.

Cecil Fredericks, an elderly night security guard about to retire from the Museum of Natural History, hires Larry despite his unpromising resume. The museum, which is rapidly losing money, plans to replace Cecil and his colleagues, Reginald and Gus, with one guard. Before his first night on the job, Cecil gives Larry an instruction manual on his job duties and warns him to "not let anything in... or out."

On his first night, Larry discovers that the museum's exhibits come to life after sunset, including: "Rexy", a Tyrannosaurus skeleton that behaves like a playful dog; Dexter, a mischievous stuffed capuchin monkey who destroys Larry's manual, along with other taxidermied animals, and later takes his keys; rival miniature civilizations depicting the American Frontier, Ancient Rome, and Ancient Maya; a chewing gum-loving Easter Island Moai who calls Larry "Dum-Dum"; American Civil War soldier mannequins; and wax models of Attila the Hun and some of his men, pyromaniacal Neanderthals, and Sacagawea, who is encased in glass and cannot hear anything. A horse-mounted Theodore Roosevelt rescues Larry from feuding miniature leaders Jedediah and Octavius, and explains that ever since an ancient Egyptian artifact—the Golden Tablet of Pharaoh Ahkmenrah—arrived in 1952, the exhibits come to life each night, but will turn to dust if left outside the museum at sunrise. As Theodore helps restore order, Larry learns that Theodore is in love with Sacagawea but is too shy to speak to her.

Cecil, Reginald, and Gus check on Larry, who has decided to quit, but Nick and Don stop by to congratulate him on his new job. Larry decides to stay for Nick's sake, and Cecil advises reading up on history. Larry is better able to control the exhibits, but is forced to extinguish a fire that the Neanderthals' had caused in their own display, while Dexter steals Larry's keys again and unlocks a window. This allows a Neanderthal to jump out the window and escape onto the street, upon seeing a group of homeless people using a fire pit. Larry again decides to quit in frustration, and is unable to save the escaped Neanderthal from disintegrating from the rising sun, while his remains are swept up by a street sweeper. Nick witnesses museum director Dr. McPhee firing Larry over the damaged Neanderthal exhibit, though Larry convinces McPhee to reconsider. McPhee gives him one last chance to prove himself and Larry clears up the misunderstanding with Nick. Rebecca Hutman, a museum guide and historian writing her dissertation on Sacagawea, believes Larry is mocking her when he tells her the museum's nighttime secret.

Larry brings Nick to the museum, intending to show him the T-rex coming to life, but nothing comes to life. They discover Cecil, Gus and Reginald stealing the tablet and have deactivated it to stop the exhibits from interfering. Like the exhibits, the elderly guards receive enhanced vitality from the tablet, and have plotted to steal it along with other valuable artifacts to fund their retirement and frame Larry for their thievery. Nick reactivates the tablet, bringing the museum back to life and a chase ensues throughout the museum, but the chase is halted when Cecil snatches the tablet away and locks Nick and Larry in the Egyptian room. Larry releases Ahkmenrah's mummy from his sarcophagus, and the pharaoh, who removes his cloth wraps to reveal himself as a fully living human, helps Larry and Nick escape. They find the other exhibits fighting amongst themselves, and Larry convinces them to unite to catch the guards and recover the tablet.

Gus and Reginald are captured, while Cecil escapes in a Pony Express stagecoach. Theodore pushes Sacagawea out of Cecil's path and is sliced in half but survives, being "made of wax." Larry pursues Cecil into Central Park, stopping him and regaining the tablet. Theodore bonds with Sacagawea as she repairs him with hot wax. Rebecca sees the exhibits returning to the museum. She realizes that Larry was telling the truth, and he later introduces her to Sacagawea. Theodore remarks that he is proud of Larry's work along with Nick. Larry laments that he was not able to save everyone, believing that Jedediah and Octavius were both killed after the latter crashed his radio-controlled car, and is surprised when they return alive and well.