Harold Cornelius Bradley was born in Oakland, California, and earned his Ph.D. in physiological chemistry from Yale in 1905. He then joined the faculty of the University of Wisconsin, Madison, as a junior professor in biochemistry and physiology. Shortly after, he was asked to become part of a team of three faculty members seeking to develop a medical education program at the university. In 1907, Bradley initiated instruction in physiology and physiological chemistry. Physiological Chemistry became an independent department in 1921 and was headed by Bradley until 1947. He retired from the University of Wisconsin in 1949.
Bradley's research encompassed a wide variety of subjects, including studies on the physiological chemistry of organisms in the phylum Mollusca, the presence of copper and zinc in marine mollusks, the presence of manganese in freshwater mussels, human pancreatic juice, the relation of enzymes to tissue synthesis, and the specificity of hemoglobins. Not only was Bradley an outstanding scientist, he was also a champion of the student community at the University of Wisconsin. He was an early and strong advocate for faculty and student out-of-class interaction, and founded the Hoofers Outing Club, the University Health Services, the Lakeshore Residence Halls, and the Memorial Union's student governance system. In 1976, the regents honored Bradley's contributions to the university by giving his name to one of the Lakeshore Residence Halls. Bradley served as president of the American Society of Biological Chemists from 1931 to 1932.