A product of the post-Second World War baby boom, Jonathan N. Harris was born in January 1950, in Manhattan, to two native New Yorkers. His father Harold, a Purple Heart combat veteran of the European and Pacific theaters of war, was educated at Harvard College and Harvard Law School before embarking upon a short-lived career as an intellectual property attorney. Mother Mildred, a graduate of New York University, trained as a dietician and chef. The family initially was established in the iconic post-war development in lower Manhattan known as Stuyvesant Town, before moving to the suburbs of northern New Jersey in July 1952.

As part of the 1950s exodus from New York City to its suburbs, Jonathan's parents relocated to New Milford, buying a newly constructed home at 711 Berkley Street. Jonathan attended the former Steuben School and Berkley Street Elementary School. The family quickly became involved in the local community, helping to found the then-fledgling New Milford Jewish Community Center and Harold serving as an elected member of the Borough Council. Jonathan's brother Paul (NMHS Class of 1974) arrived in 1956. Suffering a cardiac arrest, Harold died in February 1958 at a public meeting of the New Milford Mayor and Council. Thereafter, Jonathan and Paul were raised in a single-parent household, an atypical situation in the late 1950s and 1960s. Mildred passed away in 1996 after living in New Milford for forty-four years.

Jonathan entered New Milford High School in September 1962 as a seventh grade student. He was elected President of the Class of 1968 in his sophomore, junior, and senior years. He was a member of the National Honor Society. He participated in soccer and indoor and outdoor track and field (hurdles and high jump), and was captain of the soccer team as a senior, earning All-County honorable mention as a midfielder. Jonathan received the Knierim Award upon his graduation in June 1968.

In September 1968, Jonathan entered Brown University as a chemistry major. Within two days, he changed his concentration from science to the liberal arts, ultimately (under Brown's indulgent curriculum) creating his own concentration of American Civilization/Historical Archaeology. He conducted archeological research at the Plimoth Plantation in Plymouth, Massachusetts and at the Wellfleet Tavern dig in Wellfleet, Massachusetts. Jonathan graduated with an A.B. degree and was elected to Phi Beta Kappa in 1972.

Two weeks after graduation from Brown, in June 1972, Jonathan was married to his high school sweetheart (and prom date) Karen Gottlieb

(NMHS Class of 1968). Karen, a graduate of Wheelock College (B.A.) and Columbia University (M.A.), began her profession as a Kindergarten teacher in the Teaneck Public Schools. Karen and Jonathan will celebrate their thirty-seventh wedding anniversary in June 2009. They have two grown children, Joshua and Rachel Harris.

Descended from attorneys (his father and maternal grandfather practiced law), Jonathan attended New York University School of Law. He received a J.D. degree in 1975, passed the New Jersey bar examination, and embarked upon a one-year stint as the judicial law clerk to the Honorable Theodore W. Trautwein, Bergen County's then-Assignment Judge. In 1977, Jonathan became associated with a general practice law firm in Elmwood Park that eventually came to be known as Andora, Palmisano, Harris & Romano. Jonathan was admitted to the bar of the State of New York in 1982.

During his career in private practice as an attorney, Jonathan served as the counselor for several governmental entities and real estate developers, specializing in land use, zoning, and environmental matters. He also represented institutions and individuals in complex real estate and financing transactions. Finally, he engaged in commercial litigation in federal and state courts involving complicated business disputes.

In October 1988, Governor Thomas H. Kean nominated Jonathan to be a Judge of the Superior Court of New Jersey. Jonathan was sworn in on February 2, 1989. He is today the longest serving active judge in Bergen County. Jonathan has worked in all trial court divisions: Special Civil, Family, Criminal, and Civil. He has presided over cases as diverse as custody disputes, death penalty trials, and consumer class actions. He has tried hundreds of jury trials. Since 1997, Jonathan has managed numerous specialized dockets, including complex commercial litigation, gun permits, Mount Laurel litigation (affordable housing disputes), and actions in lieu of prerogative writs (actions against governmental agencies). In 2005, Jonathan was selected by Chief Justice Deborah T. Poritz to be one of four statewide Mass Tort judges to manage large-scale litigation including pharmaceutical products liability claims and environmental torts.

While serving as a Judge of the Superior Court, Jonathan has been a frequent lecturer at the New Jersey Judicial College, the Institute for Continuing Legal Education, and the New Jersey State Bar Association Convention. He has taught subjects that range from Jury Selection in Capital Cases, to Recent Developments in Civil Law, to Class Actions. He served on the Trial Judges Committee for Capital Causes, Supreme Court Committee for Jury Selection, and Conference of Gun Permit Judges. He has authored several published judicial opinions and was the editor of the Bench Manual for Jury Selection.

Away from the bench, Jonathan enjoys horticulture (gardening) and fine art (visiting museums).