The Prime Minister of the Commonwealth of Australia is the highest minister of the Crown, leader of the Cabinet and head of government, holding office on commission from the Governor-General of Australia. The office of Prime Minister is, in practice, the most powerful political office in Australia. Despite being at the apex of executive government in the country, the office is not mentioned in the Constitution of Australia specifically and exists through an unwritten political convention.

Barring exceptional circumstances, the prime minister is always the leader of the political party or coalition with majority support in the House of Representatives. The only case where a senator was appointed prime minister was that of John Gorton, who subsequently resigned his Senate position and was elected as a member of the House of Representatives (Senator George Pearce was acting prime minister for seven months in 1916 while Billy Hughes was overseas).

Julia Gillard is the current prime minister, leader of the Australian Labor Party, and the first female Prime Minister of Australia.

A prime minister is the most senior minister of cabinet in the executive branch of government in a parliamentary system. In many systems, the prime minister selects and may dismiss other members of the cabinet, and allocates posts to members within the government. In most systems, the prime minister is the presiding member and chairman of the cabinet. In a minority of systems, notably in semi-presidential systems of government, a prime minister is the official who is appointed to manage the civil service and execute the directives of the head of state.

In parliamentary systems fashioned after the Westminster system, the prime minister is the presiding and actual head of the government and head of the executive branch. In such systems, the head of state or the head of state's official representative (i.e. the monarch, president, or governor-general) usually holds a largely ceremonial position, although often with reserve powers.

The prime minister is often, but not always, a member of parliament and is expected with other ministers to ensure the passage of bills through the legislature. In some monarchies the monarch may also exercise executive powers (known as the royal prerogative) which are constitutionally vested in the crown and may be exercised without the approval of parliament.

Julia Eileen Gillard (born 29 September 1961) is the 27th and current Prime Minister of Australia, in office since 24 June 2010.

Gillard was born in Barry, Wales and migrated with her family to Adelaide, Australia in 1966, attending Mitcham Demonstration School and Unley High School. In 1982 Gillard moved to Melbourne. She graduated from the University of Melbourne with Bachelor of Arts and Bachelor of Laws degrees in 1986. In 1987, Gillard joined the law firm Slater & Gordon working in industrial law, before entering politics.

Gillard was elected at the 1998 federal election to the House of Representatives seat of Lalor, Victoria, for the Australian Labor Party. Following the 2001 federal election, Gillard was elected to the shadow cabinet with the portfolios of Population and Immigration. The Reconciliation and Indigenous Affairs and the Health portfolios were added in 2003. In December 2006, Kevin Rudd was elected Labor leader and Leader of the Opposition, with Gillard as deputy leader.