Hughes was born in Salem, New Jersey, the son of Pauline Mehaffey and William W. Hughes. He graduated from Penns Grove High School in 1950.Cronin, Steven; and Shopes, Richard. "REP. (WILLIAM J.) HUGHES CALLS IT QUITS ELECTED 10 TIMES TO SERVE THE 2ND DISTRICT", The Press of Atlantic City, January 25, 1994. Accessed June 26, 2011. "Hughes was born in Salem and graduated from Penns Grove Regional High School."Dunn, Phil. "Voices surfacing urging Penns Grove Middle School be renovated, not razed", Today's Sunbeam, January 15, 2011. Accessed June 26, 2011. "Many graduates of the school have gone on to positions of prominence on a national level, notably: Longtime U.S. Congressman and Ambassador to Panama William J. Hughes, actor Bruce Willis, and Olympic athletes Dave Romansky and Don Bragg." He attended Rutgers University, graduating in 1955 and earned his law degree from Rutgers Law School in 1958. He was admitted to the New Jersey bar in 1959 and commenced practice in Ocean City; served as township solicitor for Upper Township, 1959–1961; appointed assistant prosecutor for Cape May County in 1960; reappointed as first assistant prosecutor in 1961 and served until the spring of 1970;William J. Hughes, Biographical Directory of the United States Congress. Accessed June 26, 2011. appointed by the New Jersey Supreme Court to the Advisory Committee on Professional Ethics, 1972. Prior to his election to Congress in 1974, Hughes was President of the law firm of Loveland, Hughes and Garrett in Ocean City. Hughes was married to the former Nancy L. Gibson of Moorestown from 1956 until her death in 2018. The couple had four children.
