Dahl was a graduate of the University of Washington (A.B., 1936) and obtained a Ph.D. from Yale University in 1940. He served in the U.S. Army during World War II and was awarded the Bronze Star (with cluster) for distinguished service. After the war, Dahl returned to Yale, where he taught until 1986. He subsequently became Sterling Professor Emeritus of Political Science and Senior Research Scientist Sociology.