John Quincy Stilwell was born in Columbia, South Carolina, on September 20, 1933 to Edna Douglass and James Raymond Stilwell. He attended public schools in the Southeast and briefly in New Jersey, graduating in 1951 from the High School of Charleston, South Carolina. In 1954 he received an A.B. degree from the University of North Carolina at Chapel Hill with a major in English History and a minor in Naval Science, and was commissioned an Ensign in the United States Navy. Stilwell was on active duty with the Atlantic Fleet as Operations Officer and Acting Executive Officer of U.S.S. Basilone (DDE 824) until his release in May 1958. In September of that year he entered Columbia University Law School in New York City.

While a student at Columbia, Stilwell was employed as research assistant to Professor Julius Goebel, Jr., working on Volume 1 of the Holmes Devise History of the United States Supreme Court. He also edited the Columbia Law School News, a bi-monthly news organ. During the Summer of 1960, he was employed as a summer clerk at the New York law firm of Winthrop, Stimson, Putnam & Roberts, where he was permanently employed as an Associate Lawyer upon his graduation from Columbia in June 1961.

Until July 1968, Stilwell remained in the private practice of corporate and securities law. In July, 1968, he became Vice President and General Counsel of Total Energy Leasing Corporation (TELCO)(OTC) of New York and was subsequently named President. In 1971, following the privatization of TELCO, he became a general partner and counsel to TELCO's investment banker, Gibbons, Green & Rice and served on the boards of directors of several portfolio companies. In 1973 he became a principal shareholder, director and Chairman of Transcable, Inc., an owner and operator of cable television systems in New York and New Jersey. As a consultant to the Chairman, he joined Kidde, Inc., in 1979, eventually becoming Senior Vice President for Energy Operations.

From 1985 until 1987 Stilwell also served as Associate General Counsel of the Mutual Life Insurance Company of New York, following which he became a partner in the international law firm of Akin, Gump, Strauss, Hauer & Feld, L.L.P. In 1988-9, he also served as Acting General Counsel of United Savings Association of Texas, FSB (Bank United). Stilwell is married to his second wife, Nancy O'Neil, a general partner in C.C. Slaughter Farms, and has a daughter by a previous marriage and four stepsons, and six grandchildren..

In 1985, Stilwell began graduate studies in the History of Ideas program at University of Texas at Dallas (UTD), completing requirements for the M.A. in Humanities in 1988. In 1994, he received the Ph.D. in Humanities, major in History of Ideas, upon completion and successful defense of his Dissertation, "Just Conversation: The Rhetoric of Justice in Post-World War II America." Stilwell teaches the "Ethics in the Twentieth Century" ; "Introduction to Moral Philosophy;" and "Justice in America Since 1945" in undergraduate programs at UTD

Stilwell was Mayor Kirk's appointee to the Dallas County Local Workforce Development Board, serving as Chair from 1997-1999; is a member of the Board of Directors of Shared Housing Center, Inc., and has also served on the Board of Directors of Community Outreach Coalition and the Center for Help of Abused and Neglected Children (CHANCE) in Dallas. He is a member of the bar in Texas and New York and is a member of the Dallas Bar Association and the Association of the Bar of the City of New York and the American Arbitration Association.  He is actively engaged in the practice of mediation in Dallas and Collin counties, and is an active member of the Commercial Panel of the AAA, frequently acting as arbitrator of complex business disputes.  In the past ten years he has served as Arbitrator in more than 50 cases, and mediated about the same number.