Marshal of the Royal Air Force (MRAF) is the highest rank in the Royal Air Force (RAF). In peacetime it was granted to RAF officers in the appointment of Chief of the Defence Staff (CDS), and to retired Chiefs of the Air Staff (CAS), who were promoted to it on their last day of service. While surviving Marshals of the RAF retain the rank for life, the highest rank to which officers on active service are promoted is now air chief marshal. Although general promotions to Marshal of the Royal Air Force have been discontinued since the British defence cuts of the 1990s, further promotions to the rank may still be made in wartime, for members of the Royal Family and certain very senior RAF air officers in peacetime at the discretion of the monarch; all such promotions in peacetime are only honorary, however. In 2012, the then Prince of Wales was promoted to the rank in recognition of his support for his mother, Queen Elizabeth II, in her capacity as head of the armed forces (commander-in-chief), while in 2014 Lord Stirrup, who had served as Chief of the Air Staff and Chief of the Defence Staff for over seven years, was also promoted.

The Chief of the Defence Staff (CDS) is the professional head of the British Armed Forces and the most senior uniformed military adviser to the Secretary of State for Defence and the Prime Minister of the United Kingdom. The chief of the defence staff is based at the Ministry of Defence and works alongside the Permanent Under-Secretary of State for Defence, the ministry's senior civil servant. The Chief of Defence is the highest ranking officer to currently serve in the armed forces.