4th Regiment

• 1st Battalion, 258th Field Artillery (United States)
• 4/41 Evzone Regiment
• 4th Air Defense Artillery Regiment
• 4th Archipelago Regiment
• 4th Cavalry Regiment (United States)
• 4th Combat Engineer Regiment (Australia)
• 4th Continental Artillery Regiment
• 4th Field Artillery Regiment
• 4th Infantry Regiment (France)
• 4th Infantry Regiment (Greece)
• 4th Infantry Regiment (Philippine Commonwealth Army)
• 4th Infantry Regiment (Philippine Constabulary)
• 4th Infantry Regiment (United States)
• 4th Light Horse Regiment (Australia)
• 4th Marine Regiment (United States)
• 4th Mountain Artillery Regiment (Italy)
• 4th Regiment Royal Artillery
• 4th Regiment of Chemistry (Brodnica)
• 4th Regiment of Front Guard
• 4th Regiment of Line Infantry
• 4th Regiment, Royal Australian Artillery
• 4th United States Colored Infantry Regiment
• Congress Poland
• King's Own Royal Regiment (Lancaster)