Others
- Fourth Army (United Kingdom)
- Republic of China: Fourth Army (National Revolutionary Army) and New Fourth Army
- Fourth Army (France)
- Fourth Army (Ottoman Empire)
- 4th Infantry Division (Romania)
- 4th Army (Soviet Union)
- Soviet and later Russian 4th Air Army
- 4th Guards Army (Soviet Union)
- 20th Guards Army, Soviet Fourth Tank Army
- Fourth United States Army
- Fourth Army (Bulgaria)
Read more about this topic: Fourth Army