Admiral of the fleet (AF) is the highest rank in the Royal Australian Navy (RAN) and is currently held by Charles III, King of Australia.

The highest continuously-filled rank in the RAN is vice admiral, held by the Chief of Navy.

The rank evolved from the ancient sailing days and the admiral distinctions then used by the Royal Navy.

The British fleet was divided into three divisions and each designated a colour, that of red, white, or blue.

The organisation of the British fleet into coloured squadrons was abandoned in 1864, with the Royal Navy keeping the White Ensign.