Sadie G. Koninsky (August 1879 – January 2, 1952) was an American composer, music publisher, and music teacher who lived most of her life in Troy, New York. A prolific composer, she is thought to have authored over 300 pieces of music, including waltzes and marches. "Eli Green's Cakewalk", which became a popular hit when it appeared in 1898, was also the first cakewalk published by a woman. Some of her work was published under her male pseudonym, Jerome Hartman.