Ernst Athearn Bessey (February 20, 1877 – July 17, 1957) was an American mycologist, botanist and plant pathologist who served as professor of mycology and botany and dean of the graduate school at Michigan State University.
He was the son of another famous botanist, Charles Edwin Bessey.
He then moved to Germany where he did his doctoral work at the University of Halle under the supervision of Georg Klebs.
He was a founding member of the Mycological Society of America and served as its president in 1941.
Ernst Bessey Hall at Michigan State University is named in his honor.