Born in
Quincy, Massachusetts to Dr. Daniel B. Reardon and Mary Cashman Reardon, Reardon attended
Quincy High School where he was "the premier debater on the Quincy team". Reardon spent a year at
Phillips Academy in
Andover, Massachusetts, before entering
Harvard College, from which he received a
B.A., cum laude, in 1932. He received his
J.D. from
Harvard Law School in 1935, and entered the practice of law with a Massachusetts firm that year. In 1939, Reardon started his own practice and married Ann Leich. Reardon joined the
United States Navy during
World War II, achieving the rank of Lieutenant. Following the war he again practiced with a firm until 1953, when he was appointed as Counsel to Governor
Christian Herter. ==Judicial service==