List of United States federal judges by longevity of service

This is a list of Article III United States federal judges by longevity of service. The judges on the lists below were presidential appointees who have been confirmed by the Senate, and who served on the federal bench for over 40 years. It includes neither Article I judges (e.g., U.S. Tax Court, bankruptcy courts, administrative tribunals) nor Article IV judges (e.g., territorial courts).

United States Supreme Court
No justice has served actively on the United States Supreme Court for over 40 years, but six have eclipsed that timespan through senior service.

United States courts of appeals
Only Gerald Bard Tjoflat and Pauline Newman have served more than 40 years actively on an intermediate appellate court constituted by the Judiciary Act of 1869 or subsequent legislation, however many have eclipsed that timespan through senior service:

United States district courts
Judges who have sat on a United States District Court for more than 40 years.