The following table shows comparative officer ranks of World War II, with the ranks of Allied powers, the major Axis powers and various other countries and co-belligerents during World War II.

The full rank structure for commissioned officers in the British Army in the Second World War (from most senior to most junior) is given below. Field Marshall

During the course of the war, eight men would be promoted to the rank of Field Marshal, the army's highest rank. By the end of the Second World War in September 1945, over 3.5 million men and women had served in the British Army, which had suffered around 720,000 casualties throughout the conflict.

Brigadiers, Colonels, Lieutenant-Colonels and Majors were classified as field officers; Captains were classified as company officers; Lieutenants and Second Lieutenants were classified as subalterns. In the Royal Navy, Captain was also a courtesy title for the commander of a commissioned ship.

Listed in the table below are the insignia—emblems of authority—of the British Army. Badges for field officers were introduced in 1810 and the insignia was moved to the epaulettes in 1880.