Appaloosa is a 2008 American Western film based on the 2005 novel of the same name by crime writer Robert B. Parker. The film was directed by Ed Harris and co-written by Harris and Robert Knott. Appaloosa stars Harris alongside Viggo Mortensen, Renée Zellweger and Jeremy Irons. The film premiered in the 2008 Toronto International Film Festival, was released in select cities on September 19, 2008 and expanded into wide-release on October 3, 2008.

The movie shares some narrative similarities with the 1959 Western Warlock, directed by Edward Dmytryk and starring Henry Fonda, Anthony Quinn and Richard Widmark. There is also a 1966 Western named The Appaloosa which stars Marlon Brando, but the two films are unrelated.

In 1882, the small western town of Appaloosa, New Mexico, is being terrorized by local rancher Randall Bragg (Jeremy Irons), who killed Marshal Jack Bell (Robert Jauregui) and two of his deputies in cold blood when they came to his ranch to arrest two of Bragg's ranch hands. The town decides to hire lawman and town-tamer Virgil Cole (Ed Harris) and his deputy, Everett Hitch (Viggo Mortensen), to protect and regain control of the town. The council members agree to give complete control to Cole and Hitch. They begin taking control by confronting four of Bragg's men who are causing a disturbance in the saloon. Three men refuse to allow themselves to be arrested and Cole kills two of them while Hitch kills the third with his weapon of choice: an eight-gauge shotgun. The survivor surrenders his weapon to Hitch and leaves the saloon. Bragg has a meeting with Cole and Hitch and neither side will cede an inch to the other.

The Appaloosa is a horse breed best known for its colorful leopard-spotted coat pattern. There is a wide range of body types within the breed, stemming from the influence of multiple breeds of horses throughout its history. Each horse's color pattern is genetically the result of various spotting patterns overlaid on top of one of several recognized base coat colors. The color pattern of the Appaloosa is of great interest to those who study equine coat color genetics, as it and several other physical characteristics are linked to the leopard complex mutation (LP). Appaloosas are prone to develop equine recurrent uveitis and congenital stationary night blindness; the latter has been linked to the leopard complex.

Artwork depicting prehistoric horses with leopard spotting existed in cave paintings. Domesticated horses with leopard spotting patterns exists from Ancient Greece through the Early modern period; the Nez Perce people of the United States Pacific Northwest developed the original American breed. Appaloosas were once referred to by settlers as the "Palouse horse", possibly after the Palouse River, which ran through the heart of Nez Perce country. Gradually, the name evolved into "Appaloosa". The Nez Perce lost most of their horses after the Nez Perce War in 1877, and the breed fell into decline for several decades. A small number of dedicated breeders preserved the Appaloosa as a distinct breed until the Appaloosa Horse Club (ApHC) was formed as the breed registry in 1938. The modern breed maintains bloodlines tracing to the foundation bloodstock of the registry, and has a partially open stud book that allows addition of some Thoroughbred, American Quarter Horse and Arabian blood.

A film, also called a movie or motion picture, is a series of still or moving images. It is produced by recording photographic images with cameras, or by creating images using animation techniques or visual effects. The process of filmmaking has developed into an art form and industry.

Films are cultural artifacts created by specific cultures, which reflect those cultures, and, in turn, affect them. Film is considered to be an important art form, a source of popular entertainment and a powerful method for educating – or indoctrinating – citizens. The visual elements of cinema give motion pictures a universal power of communication. Some films have become popular worldwide attractions by using dubbing or subtitles that translate the dialogue into the language of the viewer.

Films are made up of a series of individual images called frames. When these images are shown rapidly in succession, a viewer has the illusion that motion is occurring. The viewer cannot see the flickering between frames due to an effect known as persistence of vision, whereby the eye retains a visual image for a fraction of a second after the source has been removed. Viewers perceive motion due to a psychological effect called beta movement.