National Security Act may refer to:

  • National Security Act, 1980, an Indian law to provide for preventive detention
  • National Security Act (South Korea), regarding seditious activities
  • National Security Act of 1947, a United States law that established the Central Intelligence Agency
  • National Security Act 2017, a Canadian act
  • National Security Act 2023 (c. 32), a UK act strengthening laws against espionage, political interference, sabotage, and assassination

National Security Law may refer to:

  • National Security Law of the United States
  • National Security Law of the People's Republic of China
  • National Security Laws of China's Special Administrative Regions, i.e.:
  • Macau National Security Law
  • 2020 Hong Kong national security law
  • National Security Law (Brazil)