Two weeks after Australian citizens voted in favour of marriage equality, the Senate passed a Same Sex Marriage Bill.
The cross-party Bill passed by 43 votes to 12. Almost all Labour senators voted in favour, as well as the Greens and members of the Liberal-National Coalition.
The Bill will now move to the House of Representatives where it is expected to pass without delay. Malcolm Turnbull's government promised some months ago to deliver a marriage equality Bill before Christmas 2017 if Australia voted yes in November's postal survey.
Labour Senate leader Penny Wong said it was an historic day for all Australians.
"Today we stand on the cusp of a remarkable achievement and an historic event, and we pause briefly to reflect, just for a moment, on what we are a part of," she said.
"We are part of an act of acceptance, an act of inclusion, an act of respect, an act of celebration - a day when this Senate declares our acceptance of our LGBTIQ brothers and sisters."
Attorney general George Brandis said the Bill would send a message of country-wide acceptance to gay Australians.
"There is nothing wrong with you. You are not unusual … There is nothing to hide," he said in an emotional speech on Tuesday.
"Whom you love is for you to decide and others to respect."