Marceline Day, nascuda Marceline Newlin (Colorado Springs, Colorado, 24 d'abril de 1908 – Cathedral City, Califòrnia, 16 de febrer de 2000), va ser una actriu de cinema nord-americana la carrera de la qual va començar quan era una nena als anys 1910 i va acabar als anys 30.

Marceline Day (born Marceline Newlin) was an American screen actress who achieved stardom in the mid 1920s, appearing opposite such diverse stars as Harry Langdon, John Barrymore, Ramon Novarro, Lon Chaney, and Buster Keaton. Her career faltered in the early 1930s and she was soon reduced to appearing in low-budget thrillers and action pictures. Day retired in the mid 1930s. She died in 2000.