It followed a historic nationwide survey that saw Australians vote overwhelmingly in favour of marriage equality.
Here is a timeline of key moments in marriage rights in Australia:
1961: Australia introduces its first Marriage Act, but it does not include a formal definition of marriage
1975: South Australia becomes the first state to decriminalise male homosexuality
1976-1997: Other states and territories decriminalise male homosexuality
2004: The Marriage Act is amended to add the definition that "marriage means the union of a man and a woman to the exclusion of all others"
2009: De facto couples are given similar rights to those who are married
2013: Federal Labor government makes it unlawful to discriminate against LGBTIQ (lesbian, gay, bi, trans, intersex, queer) people
2015: Conservative coalition government commits to a national plebiscite proposal on same-sex marriage
August 2017: Senate knocks backs national plebiscite proposal again, government pushes ahead with a national voluntary postal vote
September 2017: Ballot papers for the postal vote are sent out
November 15, 2017: Some 61.6 percent of eligible Australians vote in favour of changing the law to allow same-sex couples to marry
November 29, 2017: The upper house Senate votes in favour of legalising gay marriage
December 7, 2017: The lower House of Representatives votes overwhelmingly in support of same-sex marriage
December 9, 2017: The marriage reforms will take effect with same-sex couples able to lodge a notice to marry, and the right to marry in Australia no longer determined by sex or gender
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