A federal union is a political system of government.
Federal Union may also refer to a number of political movements:
- Federal Union (est. 1938), a British political group advocating European federalism
- Federal Union (Germany) [de] (Föderalistische Union, 1951–1957), a West German parliamentary alliance of center-right Christian and regional parties around the Zentrum
- Federalist Union (Unione Federalista), a former name (1994–1995) of the Federalist Party (1994–2008), an Italian political party
- Federal Union Army (est. 2011), an insurgent coalition in Myanmar
- Federal Union Party (est. 2013), a Burmese political party