The Army of the Ohio was the name of two Union armies in the American Civil War. The first army became the Army of the Cumberland and the second army was created in 1863.
Commanders
- Maj. Gen. Don Carlos Buell (November 15, 1861 – October 24, 1862) also department commander until March 11
- Maj. Gen. William S. Rosecrans (October 24 – October 30, 1862) became the Army of the Cumberland
- Maj. Gen. Ambrose Burnside (March 25 – December 9, 1863) also department commander
- Maj. Gen. John G. Foster (December 9, 1863 – February 9, 1864) also department commander
- Maj. Gen. John M. Schofield (February 9 – September 14, 1864) also department commander
- Maj. Gen. Jacob D. Cox (September 14 – October 22, 1864)
- Maj. Gen. John M. Schofield (October 22, 1864 – February 2, 1865)
- Maj. Gen. Jacob D. Cox (February 2 – February 9, 1865)
- Maj. Gen. John M. Schofield (February 9 – March 31, 1865) also commander of the Department of North Carolina
Major Battles and Campaigns
- Battle of Shiloh (Buell)
- Battle of Perryville (Buell)
- Morgan's Raid (Burnside)
- Knoxville Campaign (Burnside), (Foster)
- Atlanta Campaign (Schofield)
- Battle of Franklin (Schofield)
- Battle of Nashville (Schofield)
- Carolinas Campaign (Schofield)
Orders of Battle
- Shiloh Union order of battle
- Perryville Union order of battle
- Knoxville Union order of battle
- Atlanta Campaign Union order of battle
- Franklin Union order of battle
- Nashville Union order of battle
- Wilmington Union order of battle