Walter Dellinger is Chair of the Appellate Practice at O'Melveny and is a Visiting Professor of Law at Harvard University and heads the Harvard/O’Melveny Supreme Court and Appellate Practice Clinic. He is on leave from his professorship at Duke Law School. In the current term of the United States Supreme Court he argued Morgan Stanley v. Public Utility District, Exxon v. Baker, and Heller v. District of Columbia.

Dellinger served as Assistant Attorney General and head of the Office of Legal Counsel (OLC) from 1993 to 1996. He was acting Solicitor General for the 1996-97 Term of the Supreme Court. During that time, he argued nine cases before the Court, the most by any Solicitor General in more than 20 years.

He has served as Special Counsel to the Board of Directors of the New York Stock Exchange in connection with the NYSE's transformation into a publicly held company and its acquisition of an electronic trading company.

After serving in early 1993 in the White House as an advisor to the President on constitutional issues, Dellinger was nominated by the President to be Assistant Attorney General and was confirmed by the Senate in October 1993 and served for three years. As head of the OLC, Dellinger issued opinions on a wide variety of issues, including: the President's authority to deploy United States forces in Haiti and Bosnia; whether the trade agreements required treaty ratification; and a major review of separation of powers questions.

Dellinger has published articles on constitutional issues for scholarly journals including the Harvard Law Review, Yale Law Journal, and Duke Law Journal, and has written for The New York Times, The Washington Post, Newsweek, The New Republic and The London Times.

Professor Dellinger received his undergraduate degree with honors from the University of North Carolina and a J.D. from Yale Law School, where he was editor of the Yale Law Journal.