HMAS Sydney , named after the city of Sydney, New South Wales, is the third and final ship of the Hobart class air warfare destroyers used by the Royal Australian Navy (RAN).

The Hobart class is a ship class of three air warfare destroyers (AWDs) built for the Royal Australian Navy (RAN). Planning for ships to replace the Adelaide-class frigates and restore the capability last exhibited by the Perth-class destroyers began by 2000, initially under acquisition project SEA 1400, which was re-designated SEA 4000. Although the designation "Air Warfare Destroyer" is used to describe ships dedicated to the defence of a naval force from aircraft and missile attack, the destroyers are expected to also operate in anti-surface, anti-submarine, and naval gunfire support roles.