Byron Cosby (February 27, 1878–February 4, 1961) of Appleton City, Missouri, earned a Bachelor of Science in Education (1906) and a Master of Arts (1910) at the University of Missouri. After completing his Masters, he joined the faculty of the First District Normal School (later Northeast Missouri State Teachers College, now Truman State University) as Professor of Mathematics. In 1925, he moved from teaching faculty to administration, and later, as Business Manager, took over the college's fiscal operations. He left in 1936 to establish The Educational Service Bureau, an agency for teachers, in Columbia, Missouri.

He was an active member of the Missouri State Teachers Association and of the National Education Association. He was on the 1917 committee that organized the Missouri Section of the Mathematics Association of America and was the founder of Alpha Phi Sigma, the national scholastic honorary society, on the Teachers College campus in 1930. He also contributed the "Teaching of Arithmetic" article for Bufton's Universal Cyclopedia (1922).