Federal or foederal (archaic) may refer to:

In politics:

• Federal constitutional monarchy, a federation of monarchies or a federal organised monarchy
• Federal district, a subdivision under the direct control of a federal government
• Federal government, the common level of government of a federation
• Federal government of the United States
  • United States federal law
  • United States federal courts
  • Union (American Civil War)
• Federal republic, a federation of republics
• Federation, a union of states
• Federalism, a political philosophy
• Federalist Papers, critical early arguments about United States Constitution
• Government of Australia
• Government of Russia
• Union Government (Central Government) of India
• Federales (Argentina), a former political party of Argentina

Other:

• Federal architecture, an architectural style related to Georgian architecture
• Federal (album), the debut album by rapper E-40
• Federal (Amtrak), a passenger train providing an overnight Boston-Washington, D.C. service in 2003-2004
• Federal Express (passenger train), a passenger train operated by the New Haven and Pennsylvania railroads
• Federal Bureau of Investigation, the national law enforcement arm of the U.S. government
• Federal Cartridge, American ammunition manufacturer
• Federal Coach, American limousine and bus manufacturer
• Federal Express, or FedEx, a private logistical services/delivery company based in the United States of America
• Federal Records, a subsidiary label of King Records.
• Federal Reserve, central bank of the United States
• Federal Corporation, Taiwan based tire manufacturer
• Federal (film), a 2010 thriller film starring Selton Mello

Federal could mean:

• Federalism, a political philosophy
• Federation, a union of states
• Federal republic