The U.S. Department of Justice (DOJ), or United States Department of Justice, is the federal executive department responsible for the enforcement of federal law, federal prosecutions, and the administration of justice in the United States. Headed by the Attorney General, the department investigates and prosecutes federal offenses (including through U.S. Attorneys' Offices), represents the U.S. government in legal matters, establishes national criminal justice policies, and provides support to state and local law enforcement to combat crime and ensure public safety. It is functionally equivalent to justice or interior ministries in other countries.

The DOJ enforces a wide range of federal laws, including those related to foreign agents (such as the Foreign Agents Registration Act, FARA), espionage, counterterrorism, antitrust regulations, and foreign corrupt practices (through its Foreign Corrupt Practices Act, FCPA, unit), and oversees domestic enforcement of federal laws and investigations into lobbying groups. In its law enforcement activities the department has, for example, seized funds as part of operations such as Operation Bid Rig, and has pursued cases against major technology firms.

The department operates within a broader legal and political context: its alumni often enter private conservative legal practices, it has been targeted by the state of South Carolina in multiple lawsuits under Governor Nikki Haley, and in May 2013 the DOJ sent a request for information to Austrian authorities regarding bank accounts belonging to Khalilzad's wife Cheryl Benard, which triggered an Austrian money laundering investigation; no charges were filed.