12 Group RAF (12 Gp) of the Royal Air Force was a group, a military formation, that existed over two separate periods, namely the end of the First World War when it had a training function and from just prior to the Second World War until the early 1960s when it was tasked with an air defence role.

The first RAF General Officer Commanding was Brigadier-General Harold Douglas Briggs who received the appointment on promotion from Captain in the Royal Navy.

On 1 November that year the Group ceased to exist when it became the RAF (Cadet) College.

[2] It was the group responsible for aerial defence of the Midlands, Norfolk, Lincolnshire and North Wales.

The commander of 12 Group during the Battle of Britain was Air Vice Marshal Trafford Leigh-Mallory, who was a rather ambitious man.

The Big Wings met with mixed success, enough for the Air Ministry to use it as an excuse to remove Park and Air Chief Marshal Hugh Dowding from their commands on the grounds that they had mismanaged the Battle of Britain.