Malcolm Bligh Turnbull (born 24 October 1954) is an Australian former politician who was the 29th Prime Minister of Australia from 2015 to 2018.
He served twice as Leader of the Liberal Party, firstly from 2008 to 2009 when he was also Leader of the Opposition, and a second time from 2015 to 2018.
He was the MP for Wentworth in the House of Representatives from 2004 to 2018.
Turnbull graduated from the University of Sydney with a Bachelor of Arts and a Bachelor of Laws, before attending Brasenose College, Oxford as a Rhodes Scholar, earning a Bachelor of Civil Law.
For over two decades prior to entering politics, he worked as a journalist, lawyer, merchant banker, and venture capitalist.
He served as Chair of the Australian Republican Movement from 1993 to 2000, and was one of the leaders of the unsuccessful "Yes" campaign in the 1999 republic referendum.
He was first elected to the Australian House of Representatives for the Division of Wentworth in New South Wales at the 2004 federal election, and was Minister for the Environment and Water from January 2007 until December 2007.
After coming second in the 2007 leadership election, Turnbull won the leadership of the Liberal Party in September 2008 and became Leader of the Opposition.
However, his support of the Carbon Pollution Reduction Scheme proposed by the Rudd Government in December 2009 led to a leadership challenge by Tony Abbott, who defeated Turnbull by a single vote.
Though initially planning to leave politics after this, Turnbull chose to stay and was later appointed Minister for Communications in the Abbott Government following the 2013 federal election.
Citing consistently poor opinion polling for the government, Turnbull resigned from the Cabinet on 14 September 2015 and challenged Abbott, reclaiming the leadership of the Liberal Party by ten votes.
He was sworn in as Prime Minister of Australia the following day.
At the 2016 federal election, Turnbull led the Coalition to victory by a single seat, the smallest majority since the 1961 federal election.
In August 2018, a challenge by Peter Dutton led to two Liberal leadership spills.
When the second spill motion passed on 24 August 2018, Turnbull did not contest the ballot and subsequently resigned as Prime Minister.
Treasurer Scott Morrison defeated Dutton in the contest.
Turnbull resigned from parliament on 31 August 2018, triggering a by-election in his former seat of Wentworth.
The Liberal Party lost the by-election to independent candidate Kerryn Phelps, which resulted in the Coalition losing its majority in the House of Representatives.