The Bureau of Alcohol, Tobacco, Firearms and Explosives (abbreviated ATF, sometimes BATF or BATFE) is a specialized law enforcement and regulatory organization within the United States Department of Justice. Its responsibilities include the investigation and prevention of federal offenses involving the unlawful use, manufacture, and possession of firearms and explosives, acts of arson and bombings, and illegal trafficking of alcohol and tobacco products. The ATF also regulates via licensing the sale, possession, and transportation of firearms, ammunition, and explosives in interstate commerce. Many of ATF's activities are carried out in conjunction with task forces made up of state and local law enforcement officers, such as Project Safe Neighborhoods. ATF operates a one-of-a-kind fire research laboratory in Beltsville, Maryland, where full-scale mock-ups of criminal arsons can be reconstructed.

The agency is led by Michael J. Sullivan, Acting Director and Ronnie A. Carter, Deputy Director. ATF has nearly 5,000 employees and an annual budget of $1 billion.