The Australian Capital Territory has become the first part of Australia to legalise same-sex marriage.
The ACT parliament passed a bill that will allow gay couples to marry after a short debate on Tuesday.
Celebrants will now be allowed to marry same-sex couples inside the ACT, regardless of which state they live in.
Federal law, however, specified in 2004 that marriage was between a man and a woman, and the federal government is expected to challenge the move.
The move was passed in the 17-member ACT Legislative Assembly, backed by Labor and the Greens, with the Liberals voting against.
“There is no longer any excuse, if there ever was, to discriminate against same-sex couples in our community,” ACT Chief Minister Katy Gallagher told the parliament.
“They are our children, our parents, our brothers, our sisters, our leaders, our business people, our mentors and our colleagues.”
“More than anything, they are our equals. The Marriage Equality Act puts this fundamental principle and human right into law,” the Australian Broadcasting Corporation quoted her as saying.
Ms Gallagher said that the first weddings could take place by the end of the year.
Attorney-General George Brandis, however, says the local law could face a legal challenge, because it was inconsistent with the national-level Marriage Act.
Prime Minister Tony Abbott, who leads a Liberal-National coalition, opposes same-sex marriage.
His sister, however, has recently disclosed that she is engaged to her female partner.