The Freedom of Information Act (FOIA), 5 U.S.C. § 552, is a federal freedom of information law that requires the full or partial disclosure of previously unreleased information and documents controlled by the United States government upon request. The act defines agency records subject to disclosure, outlines mandatory disclosure procedures, and defines nine exemptions to the statute. The act was intended to make U.S. government agencies' functions more transparent so that the American public could more easily identify problems in government functioning and put pressure on Congress, agency officials, and the president to address them. The FOIA has been changed repeatedly by both the legislative and executive branches.

Apart from the U.S. federal government's Freedom of Information Act, the U.S. states have their own varying freedom of information laws.

While the public may be aware of news organizations' use of FOIA for reporting purposes, it makes up less than 10% of all requests with businesses, law firms, and individuals all being more frequent users.