British army division that, under the command of Henry Rawlinson (1864-1925), led the main attack on the first day of the Battle of the Somme, 1 July 1916.

The Fourth Army was a field army of the British Expeditionary Force during the First World War. The Fourth Army was formed on 5 February 1916 under the command of General Sir Henry Rawlinson to carry out the main British contribution to the Battle of the Somme.

The German Fourth Army was a field army that fought in World War II.

The Soviet Fourth Army was a Soviet field army of World War II that served on the Eastern front of World War II.

The Romanian Fourth Army was a field army that fought on the Axis side as part of the German Army Group B and later it fought on the Allies's side as part of the Soviet First Ukrainian Front during World War II.

The Fourth Army was a combat command of the National Revolutionary Army involved in the Northern Expedition of the Chinese Civil War.