A Sound Sleeper is a 1909 American comedy film directed by D. W. Griffith and produced by the American Mutoscope and Biograph Company. The short was filmed in one day in the Coytesville borough of Fort Lee, New Jersey, which at the time was a popular filming location for many early motion-picture studios in the northeastern United States. Due to the brief running time of this comedy, it was originally distributed in April 1909 on a split reel with another Biograph release, a longer dramatic film titled The Winning Coat.