Harland K. Riley was a native of Gueydan, Louisiana. He received his B.A. from Louisiana State University in 1926. He attended Iowa State College and received his masters of science in 1929. There he wrote a thesis entitled Bionomics and Control of the Greenhouse Centipede, Scutigeselia Immaculata (Newport). While in school, he participated in many societies. He was a member of the honor society Phi Kappa Phi. He also contributed to the development of the future leadership in Agriculture.

In 1931, Riley joined the faculty of Southwestern Louisiana Institute (later known as the University of Southwestern Louisiana and today the University of Louisiana at Lafayette) as an assistant professor of agriculture. He was active in the professional organizations of his field; he was one of the Charter members of Phi Kappa Phi National Honor Society at USL and served as president. In 1965, he was recognized as the outstanding teacher of horticulture in the Southern Region, when he was designated the recipient of the L.M. Ware Teaching Award. He retired in 1969 after a teaching career of 40 years.