9 Corps, 9th Corps, Ninth Corps, or IX Corps may refer to:
France
- 9th Army Corps (France)
- IX Corps (Grande Armée), a unit of the Imperial French Army during the Napoleonic Wars
Germany
- IX Corps (German Empire), a unit of the Imperial German Army prior to and during World War I
- IX Reserve Corps (German Empire), a unit of the Imperial German Army during World War
- IX Army Corps (Wehrmacht), a unit in World War II
- IX SS Mountain Corps, a unit in World War II
Other countries
- IX Corps (India)
- IX Corps (Ottoman Empire)
- 9th Army Corps (Ukraine)
- IX Corps (United Kingdom)
- IX Corps (Union Army)
- IX Corps (United States)
- 9th Corps (Yugoslav Partisans)
See also
- List of military corps by number