He attracted 45 votes to Peter Dutton's 40. Josh Frydenberg has been elected deputy leader.
But what do we know about our new PM?
Morrison, who grew up in Sydney' South, is a member of ShireLive evangelical church and has been vocal about his Christian beliefs.
“Growing up in a Christian home, I made a commitment to my faith at an early age,” he said in his first speech.
“My personal faith in Jesus Christ is not a political agenda ... for me, faith is personal, but the implications are social.
“From my faith I derive the values of loving-kindness, justice and righteousness, to act with compassion and kindness, acknowledging our common humanity and to consider the welfare of others; to fight for a fair go for everyone to fulfil their human potential and to remove whatever unjust obstacles stand in their way, including diminishing their personal responsibility for their own wellbeing; and to do what is right, to respect the rule of law, the sanctity of human life and the moral integrity of marriage and the family.”
Born in the Eastern suburbs of Sydney, Morrison is the son of a police officer.
He studied a Bachelor of Science then pursued a career in the tourism industry - and yes, he was involved in Lara Bingle's "Where the bloody hell are you?" campaign while working for Tourism Australia.
Morrison entered parliament in 2007 where he was won preselection in the seat of Cook in Sydney’s Sutherland Shire.
In 2009, he became shadow minister for immigration and citizenship in the Abbott government.
In 2014, he was appointed Minister for Social Services but became treasurer in 2015 when Malcolm Turnbull replaced Tony Abbot as PM.
Turnbull tweeted that once the 43 signatures from the Liberal Party were verified, he would call a meeting.