Helena Smith Dayton (often hyphened as Helena Smith-Dayton) (1883–1960) was an American film maker, painter and sculptor working in New York City who used fledgling stop motion and clay animation techniques in the 1910s and 1920s, one of the earliest animators (and the first American woman) to experiment with clay animation. Her "clay cartoons" were humorous in nature, and Dayton was featured in the "Humorist Salons" in New York City. She spent the end of World War I in Paris managing an YMCA canteen for soldiers. She was a published author, ranging in genre from journalism to plays to a guide to New York City.