William B. Harrington graduated from Washington and Lee University with A. B. degree and then went on to Harvard University. At Harvard, Harrington graduated with a LL. B. degree. At school he was a member of the Delta Tau Delta fraternity and the 13 club. He married Ruth Cadwallender Harrington. They lived in Frances Apartments, Columbus, Mississippi. In 1941 they had a daughter Mary Patricia Claire Harrington