The mission of the Department of Justice (DOJ) is to enforce the law and defend the interests of the United States according to the law; to ensure public safety against threats foreign and domestic; to provide federal leadership in preventing and controlling crime; to seek just punishment for those guilty of unlawful behavior; and to ensure fair and impartial administration of justice for all Americans.

The DOJ is comprised of 40 component organizations, including the Drug Enforcement Administration, the Federal Bureau of Investigation, the U.S. Marshals, and the Federal Bureau of Prisons. The Attorney General is the head of the DOJ and chief law enforcement officer of the federal government. The Attorney General represents the United States in legal matters, advises the President and the heads of the executive departments of the government, and occasionally appears in person before the Supreme Court.

With a budget of approximately $25 billion, the DOJ is the world's largest law office and the central agency for the enforcement of federal laws.