I
- Battle of Iena - 1806 - Napoleonic Empire Wars
- Battle of Ilipa - 206 BC - Second Punic War
- Battle of Inkerman - 1854 - Crimean War
- Battle of Intombe - 1879 - Anglo-Zulu War
- Battle of Inverlochy - 1431
- Battle of Inverlochy - 1645 - English Civil War
- Battle of Issus - 333 BC - Wars of Alexander the Great
- Battle of Ituzaingo - 1827 - Uruguayan War of Independence
- Battle of Iwo Jima - 1945 - World War II
- Battle of the Iron Bridge - 637 - Byzantine–Arab Wars
- Battle of the Ironclads (a.k.a. Monitor vs. Merrimack, Battle of Hampton Roads) - 1862 - American Civil War
- Battle of Isandhlwana - Anglo-Zulu War
- Battle of Isonzo (489) - Ostrogoth invasion of Italy
- Battles of the Isonzo - World War I - a series of eleven related battles, ending with the Battle of Caporetto
Read more about this topic: List Of Battles (alphabetical)