Geoff Stewart's practice focuses on complex litigation. He has represented clients in matters involving business and other torts, the federal securities laws, the United States copyright laws, and international commercial disputes.

In the area of intellectual property, Geoff was counsel to plaintiffs in Eldred v. Ashcroft, 537 U.S. 186 (2003), which challenged the constitutionality of copyright term extensions; Yahoo! in a leading case involving internet music services; and the artist Shepard Fairey in litigation involving Fairey's creation of the iconic Obama Hope poster. Prior to joining Jones Day, he represented plaintiffs in Apfel v. Prudential Bache Securities, 81 N.Y. 2d 470 (1993), which is a staple of law school contract courses.

Much of Geoff’s practice is international. Between 2007 and 2011, he represented Prince Jefri Bolkiah of Brunei in global litigation involving claims of breach of fiduciary duty and enforcement of judgments. Since 2009, Geoff has advised Satyam Computer Services in securities law cases in New York and England. He also has represented clients in arbitrations involving domestic and international disputes and has served as an arbitrator himself.

From 1981 to 1983, Geoff was Deputy Assistant Attorney General for the Justice Department's Office of Legal Policy. From 1987 to 1990, he was Associate Independent Counsel for the Iran Arms Sale/Contra Diversion Investigation, concentrating on matters involving the U.S. State Department and the Central Intelligence Agency.

Geoff has served on the boards of several schools and foundations. He is a director of the American India Foundation, which funds literacy, livelihood, and public health projects in India. In 2011, he became a member of the Chapter of the Washington National Cathedral.