Mark J. Cohen (November 19, 1942 – December 18, 1999) was a realtor and a collector of comic books and comic book art, and a prominent cartoonists' agent and dealer in original comics art. He was an occasional contributor to the Gasoline Alley comic strip. Cohen was a native of Stockton, California. As a collector of cartoon art, Cohen amassed an estimated 9,500 items of original Mad original art. His collections of comic book art were considered among the best in the country, and parts of his collections were put on national tours.