20th Corps, Twentieth Corps, or XX Corps may refer to:
- XX Corps (German Empire)
- XX Corps (Ottoman Empire)
- XX Corps (United Kingdom)
- XX Corps (United States)
- XX Corps (Union Army), a unit in the American Civil War
- XX Army Corps (Wehrmacht)
- XX Motorised Corps (Italy)
- 20th Army Corps (Russian Empire)
- 20th Army Corps (Ukraine)
See also
- List of military corps by number
- 20th Army (disambiguation)
- 20th Brigade (disambiguation)
- 20th Division (disambiguation)
- 20th Regiment (disambiguation)
- 20 Squadron (disambiguation)