Mark Alfred Carleton (Ohio, United States 7 March 1866 – Paita, Peru 25 April 1925) was an American botanist and plant pathologist, most notable for his introduction of hard red wheats and durum wheats from Russia into the American wheatbelt. Carleton become the first president of the American Society of Agronomy. In 1916, he published a textbook entitled The Small Grains which has been called masterly. The standard author abbreviation Carleton is used to indicate this person as the author when citing a botanical name.