13th Brigade
- 13 Squadron (disambiguation)
- 13th Army (disambiguation)
- 13th Battalion (disambiguation)
- 13th Brigade (Australia)
- 13th Brigade (Japan)
- 13th Cavalry Brigade (British Indian Army)
- 13th Demi-Brigade of Foreign Legion
- 13th Division (disambiguation)
- 13th Group (disambiguation)
- 13th Indian Cavalry Brigade
- 13th Indian Infantry Brigade
- 13th Infantry Brigade (Hungary)
- 13th Infantry Brigade (United Kingdom)
- 13th Infantry Brigade (United States)
- 13th Light Brigade (Netherlands)
- 13th Light Tank Brigade
- 13th Mounted Brigade
- XIII Brigade, Royal Horse Artillery
- XIII International Brigade