Clifford M. Hardin was born October 9, 1915, near Kingston, Indiana. He earned a B.S. (1937), an M.S. (1939), and a Ph.D. (1941) from Purdue University.

Hardin taught and conducted research in agricultural economics from 1944 to 1948, prior to becoming assistant director, and then director, of the Agricultural Experiment Station at Michigan State University (1948-1953). Hardin was Michigan State's dean of agriculture (1953-1954), before moving on to become chancellor of the University of Nebraska in 1954.

President Richard Nixon appointed Hardin secretary of agriculture in 1969, and Hardin remained in that post until 1971.