The cabinet under Prime Minister Malcolm Turnbull approved the referendum on Tuesday, EFE news reported.
The proposal for the refrendum will be submitted to the ruling coalition MPs, but those who are in favour of the legalisation consider that financing the campaigns with public money will be counterproductive.
The referendum also depends on the approval of the necessary legislation by the Labour opposition in Parliament.
Labor opposition advocates that same-sex marriage should be directly legalised without a plebiscite as it could encourage homophobia.
"A 'no' campaign would be an emotional torment for gay teenagers and if one child commits suicide over the plebiscite, then that one is too many," Labor party opposition leader Bill Shorten said.
Australia, where several states allow civil union, was criticised by several organisations for being slow in legalisation of marriages between same sex couples.
In December 2013, Australia's High Court annulled a law allowing same sex marriages on the ground that it contravened the cuntry's marriage laws.
Similar legislative proposals have also failed in the states of Tasmania and in New South Wales.
