Quentin Bryce was Friday sworn in at Parliament House in Canberra as Australia's 25th governor-general, as the first female to fill the position, reported dpa.
Bryce, 65, is now the representative in Australia of Britain's Queen Elizabeth II.
The former Queensland state governor succeeds Major General Michael Jeffery in what is largely a ceremonial role.
The ruling Labor Party supports Australia becoming a republic and there is a likelihood that Bryce, who will serve for five years, will be the last governor general.