16 mm film refers to a popular, economical gauge of film used for motion pictures and non-theatrical (for instance, industrial or educational) film making. 16 mm refers to the width of the film. Other common film gauges include 8 mm and 35 mm.

16 mm film was introduced by Eastman Kodak in 1923 as an inexpensive amateur alternative to the conventional 35 mm film format. During the 1920s the format was often referred to as sub-standard film by the professional industry. Initially directed toward the amateur market, Kodak hired Willard Beech Cook from his 28 mm Pathescope of America company to create the new 16 mm Kodascope Library. In addition to making home movies, one could buy or rent films from the library, one of the key selling aspects of the format. As it was intended for amateur use, 16 mm film was one of the first formats to use acetate safety film as a film base, and Kodak never manufactured nitrate film for the format due to the high flammability of the nitrate base. 35 mm nitrate was discontinued in 1952.