In contemporary Australian state constitutions, a lieutenant governor is a standing appointment for a deputy governor, to act in place of the governor if they are unable, unavailable or unwilling to act. There is no deputy for the Commonwealth governor-general; instead, the senior state governor takes up a standing appointment to act as Administrator of the Commonwealth. Historically, a lieutenant governor could also be the deputy of the New South Wales Governor in a particular territory.
Constitutionally Lieutenant-Governors, Administrators and the Chief Justices of the State Supreme Courts are normally separate offices[1][2] in the Australian states, however in many states most notably New South Wales,[3] the role of Lieutenant-Governor is played by the Chief Justice of the Supreme Court. In 2001, the Constitution of Queensland was amended to restore the office of Lieutenant-Governor in that state. When a Governor-General or state Governor dies, resigns, or is absent, an Administrator, or acting Governor, would be appointed. In the case of the Governor-General this officer is styled as an Administrator, while in the case of State Governors this officer may either be an Administrator or the Lieutenant-Governor. The state Lieutenant-Governors/Administrators have no standing powers but stand ready to take up the Governor's role.
An additional office is available in some states, such as the Governor's Deputy in Victoria. This office can exercise only the powers the governor delegates to them.
When the Governor-General is overseas or on leave, the longest serving State governor acts as Administrator of the Commonwealth. Until she retires or resigns, the longest-serving State governor is Professor Marie Bashir of New South Wales, who has served since 1 March 2001. The second-longest-serving State governor until he retires or resigns is South Australia's Rear Admiral Kevin Scarce, who has served since 8 August 2007.
Historically, in the early and mid 19th centuries, lieutenant-governors ran Australasian sub-colonies that were initially subordinate to the colony of New South Wales, such as Van Diemen's Land (Tasmania) or the Bay of Islands (New Zealand).