List of British divisions in World War II

During the Second World War, the basic tactical formation used by the majority of combatants was the division. It was a self-contained formation that possessed all the required forces for combat, which was supplemented by its own artillery, engineers, communications and supply units. On 3 September 1939, at the start of the war, the United Kingdom had 2 armoured, 24 infantry and 7 anti-aircraft divisions. The anti-aircraft divisions were not comparable in role to formations that were intended for combat such as infantry divisions. In September, the British Army stated that 55 divisions (a mix of armoured, infantry and cavalry) would be raised to combat Germany. The UK would provide 32 of these formations and the remainder would be raised by the Dominions and India.

In 1941, this goal was adjusted to 57 divisions, with the UK to provide 36. By the end of 1941, the UK had met its quota. Over the course of the war, 85 divisional formations were raised although they did not all exist simultaneously and not all of them were combat formations. For example, the 12th Division (SDF) was raised to protect the lines of communication behind fighting formations. Several divisions were created when a division of one type was converted into another, for example the 42nd (East Lancashire) Infantry Division was converted into the 42nd Armoured Division. Others, such as the 79th Armoured Division, were not intended to act as a fighting formation. Instead, it acted in an administrative capacity for dispersed units that were engaged in combat. The 85 divisional formations included 2 airborne, 12 anti-aircraft, 11 armoured, 1 cavalry, 10 coastal defence (known as County Divisions) and 49 infantry divisions. At the end of the war, in 1945, the British Army had 24 divisions.