Gregory George Katsas is a United States Circuit Judge of the U.S. Court of Appeals for the District of Columbia Circuit.
Judge Katsas was appointed to the D.C. Circuit in December 2017. He graduated from Princeton University and Harvard Law School, where he was an executive editor on the Harvard Law Review. Between 1989 and 1992, he served as a law clerk to Judge Edward Becker on the Third Circuit, to then-Judge Clarence Thomas on the D.C. Circuit, and to Justice Thomas on the Supreme Court. Between 1992 and 2001, he was an associate and then partner in the Washington office of Jones Day, where he specialized in appellate and complex civil litigation. Between 2001 and 2009, he served in many senior positions in the Department of Justice, including as Assistant Attorney General for the Civil Division and as Acting Associate Attorney General. In 2009, he returned to Jones Day. From January to December 2017, he served as Deputy Assistant to the President and Deputy Counsel to the President.
Before joining the bench, Judge Katsas argued more than 75 appeals, including three cases in the Supreme Court, 13 cases in the D.C. Circuit, and cases in every other federal court of appeals. By appointment of the Chief Justice, he served on the Advisory Committee on Appellate Rules from 2013 to 2017. In 2016, he was elected to membership in the American Academy of Appellate Lawyers.