The United States Department of Justice (DOJ), also known as the Justice Department, is a federal executive department of the U.S. government that oversees the domestic enforcement of federal laws and the administration of justice. It is equivalent to the justice or interior ministries of other countries.

The Justice Department contains most of the United States' federal law enforcement agencies, including the Federal Bureau of Investigation, the U.S. Marshals Service, the Bureau of Alcohol, Tobacco, Firearms and Explosives, the Drug Enforcement Administration, and the Federal Bureau of Prisons. The department also has eight divisions of lawyers who represent the federal government in litigation: the Criminal, Civil, Antitrust, Tax, Civil Rights, Environment and Natural Resources, National Security, and Justice Management Divisions. The DOJ includes the U.S. Attorneys' Offices for each of the 94 U.S. federal judicial districts.