A sound film is a motion picture with synchronized sound, or sound technologically coupled to image, as opposed to a silent film. The first known public exhibition of projected sound films took place in Paris in 1900, but decades would pass before reliable synchronization was made commercially practical. The first commercial screening of movies with fully synchronized sound took place in New York City in April 1923. In the early years after the introduction of sound, films incorporating synchronized dialogue were known as "talking pictures," or "talkies." The first feature-length movie originally presented as a talkie was The Jazz Singer, released in October 1927.

By the early 1930s, the talkies were a global phenomenon. In the United States, they helped secure Hollywood's position as one of the world's most powerful cultural/commercial systems. In Europe (and, to a lesser degree, elsewhere) the new development was treated with suspicion by many filmmakers and critics, who worried that a focus on dialogue would subvert the unique aesthetic virtues of soundless cinema. In Japan, where the popular film tradition integrated silent movie and live vocal performance, talking pictures were slow to take root. In India, sound was the transformative element that led to the rapid expansion of the nation's film industry—the most productive such industry in the world since the early 1960s.