Visiting judge
A visiting judge is a judge appointed to hear a case as a member of a court to which he or she does not ordinarily belong. In United States federal courts, this is referred to as an assignment "by designation" of the Chief Justice of the United States or the Circuit Chief Judge, and is authorized by or .
In many United States Courts of Appeals it is not uncommon for a district judge to sit on a panel as a visiting judge; less frequently it is a judge from another circuit. Retired Supreme Court justices have done the same, including Justices O'Connor and Souter, and very unusually, sitting Justices. This is sometimes done to ease caseload pressures, and sometimes for experience.
