The Australian Capital Territory became the first jurisdiction in Australia to legalise same-sex marriage with a bill passing the ACT parliament by just one vote on Tuesday.
Under the law, same-sex couples from across Australia will be able to marry in the ACT, which includes the national capital Canberra, after giving four weeks notice.
Chief Minister of the Australian Capital Territory Katy Gallagher told parliament that there was "no longer any excuse if there ever was to discriminate against same sex couples in our community".
"They are our children, our parents, our brothers, our sisters, our leaders... more than anything, they are our equals," she said to cheers from the crowd in the parliamentary gallery.
The national government, led by conservative Prime Minister Tony Abbott, is expected to challenge the laws in the High Court of Australia, despite eleventh hour amendments made to strengthen the marriage equality bill against any challenges.
In September 2012, laws to legalise same-sex marriage failed to pass in Australia's national parliament.
New Zealand became the first country in the Asia-Pacific region to legalise same-sex marriage in April this year.
Other countries were such marriages are legal include Canada, Spain, Sweden and some states in the United States.