One Hundred and One Dalmatians (also known as 101 Dalmatians) is a 1961 American animated adventure comedy film produced by Walt Disney Productions with distribution by Buena Vista Distribution. Adapted from Dodie Smith's 1956 novel The Hundred and One Dalmatians, the film was directed by Hamilton Luske, Clyde Geronimi, and Wolfgang Reitherman in his feature-length directorial debut, from a script by Bill Peet. It features the voice talents of Rod Taylor, J. Pat O'Malley, Betty Lou Gerson, Martha Wentworth, Ben Wright, Cate Bauer, Dave Frankham, and Fred Worlock. The film's plot follows Pongo and Perdita, two British Dalmatians who give birth to a litter of fifteen puppies, who are later kidnapped by the obsessive socialite Cruella de Vil, wanting to make their fur into coats. Pongo and Perdita set out on a cross-country rescue mission to save the litter from the maniacal Cruella. They rescue 84 additional Dalmatians in the process, bringing the total to 101.

One Hundred and One Dalmatians was released in theaters on January 25, 1961, to positive reviews from critics and was a box-office success, grossing $14 million domestically in its original theatrical run. It became the first animated feature to earn over $10 million during its initial release, and became the eighth-highest-grossing film of the year in the North American box office and the highest-grossing animated film when reissues of films are not counted. Aside from its box-office revenue, the employment of inexpensive animation techniques, such as using xerography during the process of inking and painting traditional animation cels, kept production costs down. Counting reissues, the film grossed $303 million worldwide, and when adjusted for inflation, is the twelfth-highest-grossing film in the North American box office and the second-highest-grossing animated film globally, as well as being the highest-selling traditionally animated film of all time at an estimate of over 199,800,000 sold tickets.

The success of the film made Disney expand it into a media franchise, with a live-action remake released in 1996, followed by a sequel in 2000. A direct-to-video animated sequel to the 1961 film, 101 Dalmatians II: Patch's London Adventure, was released in 2003. Two animated television series based on the franchise were also produced, with 101 Dalmatians: The Series in 1997 and 101 Dalmatian Street in 2019. A live-action reboot, Cruella, was released in 2021.

In the year of 1957, aspiring songwriter Roger Radcliffe lives in a bachelor flat near Regent's Park in London with his pet Dalmatian, Pongo. Deciding both of them need a "mate", Pongo watches women and their dogs in the street. Noticing a young woman named Anita and her Dalmatian Perdita, he drags Roger to the park to arrange a meeting. Despite a tumultuous first encounter, Roger and Anita fall in love, and soon marry, with Pongo and Perdita attending.

The Radcliffes hire a nanny and move into a small townhouse near Regent's Park. After Perdita becomes pregnant with a litter of 15 puppies, the Radcliffes are visited by Cruella de Vil, Anita's arrogant, fur-obsessed friend from their school years, who demands to know when Perdita's puppies will arrive. Distrustful of Cruella, Perdita begins to regret the idea of having puppies. When the puppies are finally born, Cruella returns demanding to buy them, but Roger firmly denies her offer, causing an outraged Cruella to swear revenge.

Several weeks later, Cruella makes good on her threat by secretly hiring Jasper and Horace Badun, two burglar brothers, to steal the puppies. With the police unable to find the puppies or prove Cruella was involved, Pongo and Perdita use the "Twilight Bark", a canine gossip line, to solicit help from the other dogs in London, and eventually all of England.

Elsewhere on the farm of a retired cavalry officer in Suffolk, the Colonel, an Old English Sheepdog, along with his feline compatriot Sergeant Tibbs, investigate a nearby mansion called Hell Hall, where puppies had been heard barking two nights earlier. In the mansion, Tibbs finds the 15 stolen Dalmatian puppies along with 84 others, who were bought legally from pet shops. After the Colonel sends word of the puppies' location back to London, Pongo and Perdita travel to Suffolk and arrive at Hell Hall, where it is revealed that Cruella intends to have the Baduns kill the puppies in order to make them into dog-skin fur coats. Pongo and Perdita battle Horace and Jasper while the Colonel and Tibbs guide the puppies out of the house. Upon reuniting with their own litter of puppies, Pongo and Perdita decide to adopt the other 84 puppies to protect them from Cruella and the Baduns.

The Dalmatians start their homeward trek, pursued by Cruella and the Baduns. They eventually make their way to Dinsford, where they meet a Black Labrador who offers them a ride in a moving van bound for London. Cruella and the Baduns arrive, prompting Pongo to have his entire family roll in a sooty fireplace to disguise themselves as other Labradors. While the Dalmatians board the van, their cover is blown when melting snow causes some of their soot to be washed off. Enraged, Cruella pursues the van in her car and tries to ram it off the road, but the Baduns, attempting to do the same with their lorry, end up colliding with her. Both vehicles crash into a snowy ditch as the van drives away.