American physiologist who shared the Nobel Prize for Physiology or Medicine in 1956 with Werner Forssmann (Forssmann, Werner) and André F. Cournand (Cournand, André F.). Cournand and Richards adapted Forssmann's technique of using a flexible tube (catheter (catheterization)), conducted from an elbow vein to the heart, as a probe to investigate the heart.

Richards received an A.B. degree from Yale University in 1917 and later studied at Columbia University's College of Physicians and Surgeons (M.A., 1922; M.D., 1923). After a hospital internship and a brief study in England, he returned to Columbia University in 1928 and taught there from 1947 to 1961. From 1945 to 1961 he worked at Bellevue Hospital, New York City, where he met Cournand. Their use and perfection of Forssmann's method, known as cardiac catheterization, permitted them to measure blood pressure and other conditions inside the heart.