Katsas was born in 1964 in Boston to Greek immigrant parents.
He earned a Bachelor of Arts cum laude from Princeton University and a Juris Doctor cum laude from Harvard Law School, where he was executive editor of the Harvard Law Review and an editor of the Harvard Journal of Law & Public Policy.

Early in his career, he served as a law clerk to Justice Clarence Thomas, both at the District of Columbia Circuit and the United States Supreme Court, and to Judge Edward Roy Becker of the United States Court of Appeals for the Third Circuit.
From 2001 to 2009, he served in many senior positions in the United States Department of Justice, including Assistant Attorney General for the Civil Division and Acting Associate Attorney General.

Prior to joining the White House Counsel's Office, he was a partner at Jones Day, where he specialized in civil and appellate litigation.
He has argued more than 75 appeals, including three cases in the U.S. Supreme Court.
Katsas was born in 1964 in Boston to Greek immigrant parents. He earned a Bachelor of Arts cum laude from Princeton University and a Juris Doctor cum laude from Harvard Law School, where he was executive editor of the Harvard Law Review and an editor of the Harvard Journal of Law & Public Policy.
Early in his career, he served as a law clerk to Justice Clarence Thomas, both at the District of Columbia Circuit and the United States Supreme Court, and to Judge Edward Roy Becker of the United States Court of Appeals for the Third Circuit. From 2001 to 2009, he served in many senior positions in the United States Department of Justice, including Assistant Attorney General for the Civil Division and Acting Associate Attorney General.
Prior to joining the White House Counsel's Office, he was a partner at Jones Day, where he specialized in civil and appellate litigation. He has argued more than 75 appeals, including three cases in the U.S. Supreme Court.
Gregory G. Katsas