1st Army Corps
- 1st Army (disambiguation)
- 1st Army Corps (Armed Forces of South Russia)
- 1st Army Corps (Armenia)
- 1st Army Corps (Azerbaijan)
- 1st Army Corps (France)
- 1st Army Corps (Russia)
- 1st Army Corps (Russian Empire)
- 1st Army Corps (Soviet Union)
- I Army Corps (Greece)
- I Army Corps (Wehrmacht)
- I Corps (British India)
- I Corps (India)
- I Corps (Polish Armed Forces in the West)
- I Corps (Sri Lanka)
- I Corps (United Kingdom)
- I Corps (United States)
- I Corps (disambiguation)
- Russian separatist forces in Donbas