Cassius Marcellus Coolidge (September 18, 1844 – January 13, 1934), professionally best known as C. M. Coolidge, was an American visual artist, best known for his paintings in the "dogs playing poker" genre. He was also known as Cash Coolidge (sometimes spelled Kash).
Born in Philadelphia, New York to abolitionist Quaker farmers, Coolidge was known by the nickname "Cash" to friends and family. While he had no formal training as an artist, his natural aptitude for drawing led him to create cartoons for his local newspaper when in his twenties. He is credited with creating comic foregrounds, life-size cutouts into which one's head was placed so as to be photographed as an amusing character, common at midways and carnivals.