Raised by a single father, Malcolm Turnbull graduated with a law degree from Sydney University before continuing his legal studies at Oxford University in the United Kingdom.
After making his mark in law, Turnbull turned to business and made a small fortune by selling his stake in former Internet Service Provider OzEmail, of which he was co-founder and chairman, to former U.S. telecoms company WorldCom, for a reported $520 million.
Unlike Abbott, Turnbull draws on academics rather than faith. Here are five other things to know about Australia's newest prime minister.
Turnbull was elected to Parliament in the 2004 federal election. Within three years, he had entered Cabinet and in September 2008 was elected Liberal Party leader while in opposition. At the time, Kevin Rudd was Australian Prime Minister, but was ousted in 2010.
Turnbull was himself ousted as Liberal Party leader in December 2009, by none other than Abbott. It all came down to a single party room vote (42 - 41), and the key issue was Turnbull's support for the emissions trading scheme (ETS) proposed by the Rudd government.
Abbott was vehemently opposed to it.
2. He's strong on climate change
The ETS and Australia's policies on climate change have long been a point of contention between the country's main political parties.
In the past, Turnbull has attacked Abbott's record on the environment, and has called for a "strong, credible policy framework" to cut greenhouse gas emissions.
"Climate change is the ultimate long term problem. We have to make decisions today, bear costs today so that adverse consequences are avoided, dangerous consequences, many decades into the future," he wrote in an opinion piece in 2010.
Abbott has been referred to as a climate change "villain,"
and his government's 2030 emissions targets have been labeled "pathetic."
3. He supports same-sex marriage
Turnbull also differs from Abbott on same-sex marriage. In a blog post last month
, he said that if a "conscience" vote was held on the matter -- a free vote of party policy -- he would vote for same-sex marriage. Abbott ruled that option out
, but said if he won the election, the question would be put to the people.
In a blog post one month ago, Turnbull wrote that his own view was that "it would be better if same-sex marriage were not a contentious issue at the next election."
4. He wants more women in power
Turnbull recently became a "Male Champion of Change,"
one of a team of high-profile men who are using their positions of power to promote greater gender diversity.
"Increasing the number of women in politics is not solely a 'women's issue' -- it is in the national interest for Australia to have access to 100% of the nation's talent pool, regardless of gender," Turnbull recently wrote in his blog.
Abbott stirred the wrath of many of the nation's females when he appointed himself Minister for Women, soon after taking power. Last year, Abbott was caught winking at an ABC radio presenter
who was introducing a sex phone worker who had called in to ask him about the budget. The "mistake" was held up as more evidence of his alleged sexism.
5. He's not universally loved
While seen as a populist, Turnbull has vehement enemies.
After he announced his challenge, former Victorian Premier Jeff Kennett made no attempt to mask his disgust on Twitter.
"Malcolm Turnbull, You self centered, selfish individual. It has always been about you," Kennett tweeted.
"Selfish undisciplined individual. If you win the spill you lose. You have ignored the Govts wins and put your own interests above all."