in the United States, any of the basic trial-level courts of the federal judicial system. The courts, which exercise both criminal and civil jurisdiction, are based in 94 judicial districts throughout the United States. Each state has at least one judicial district, as do the District of Columbia and Puerto Rico, and a populous state may have as many as four districts. The number of judges varies widely from district to district.

As of 2003, Congress had authorized some 650 district court judgeships. As required by Article III of the Constitution of the United States (Constitution of the United States of America), the judges of district courts are nominated by the president and confirmed by the Senate and hold their offices “during good Behaviour.” Magistrate judges, who are appointed by federal district judges on a full-time basis for eight-year terms or on a part-time basis for four-year terms, play an increasingly important role in assisting district judges. Indeed, with the consent of the parties to the case, they may conduct trials and enter decisions themselves.

Decisions of the district courts are normally subject to appeal, typically to the United States Court of Appeals for the region in which the district court is located.