The 'Yes' vote on allowing gay couples to tie the knot won in all six Australian states, despite the most senior figure of the country's Anglican Church warning such a move would have "irreparable consequences" effects.
Reacting to the result on Wednesday, Archbishop of Sydney Dr Glenn Davies said in a video posted online: "Although this won't prevent me from continuing to teach that marriage, in God's good design, is between a men and a woman... the reality will be, in a very short period of time, our Parliament will legislate for same-sex marriage."
Support for the legalisation of same-sex marriage varied between states, ranging from 57.8 per cent in New South Wales to 74 per cent in the Australian Capital Territory.
The Australian Parliament is expected to vote before the end of the year on a change to legislation which will enshrine same-sex marriage in law.
Turnout in the two-month postal vote was 79.5 per cent, higher than the 2016 referendum on the UK's EU membership and the most recent US election.
Speaking in Canberra, Prime Minister Malcolm Turnbull said: "Australians have voted yes for fairness, they have voted yes for commitment, they have voted yes for love.
"Now it's up to us here in the Parliament of Australia to get on with it, to get on with the job the people have asked us to do and get it done this year, before Christmas."