Labor is set to gain a 77th seat, enough for Prime Minister Anthony Albanese to form a majority government and evade making deals with the crossbench to find a speaker.
The ABC has projected Labor's Fiona Phillips will win Gilmore, the final seat in doubt, narrowly defeating former NSW state transport minister Andrew Constance.
The 47th Parliament of Australia will be made up of 77 Labor seats, 58 Coalition seats, four Greens seats and 12 other crossbenchers.
Earlier, Mr Albanese joked with his colleagues that if Ms Phillips won the seat the party would no longer refer to her as Fiona but instead as "77".
ABC election analyst Antony Green said there were not enough uncounted votes left for Mr Constance to turn around Labor's lead.
But the count remains tight, with Ms Phillips leading by just 200 votes.
An automatic recount is triggered if the margin is less than 100 votes.
The final win for the Labor Party comes as Mr Albanese announces his ministry, following the first Labor caucus of the new government.
Labor had enough seats to govern in its own right, but with 76 it would have needed to find a speaker from the crossbench.
Several independents had been sounded out for the role.
The greatly expanded crossbench was one of the most significant results of the federal election, as several independent candidates successfully toppled established Liberal politicians on a promise to force government accountability and climate action.
Independent MP Rebekha Sharkie told the ABC on Tuesday afternoon that Labor's majority would not diminish the influence of the crossbench.
"For the last two parliaments, for the majority of the time, the government, the previous government had the majority but they still needed to talk to the crossbench because they are very tight numbers and whether it is 76 or 77, in this parliament would still be tight," Ms Sharkie said.
"But I think also more broadly that Anthony Albanese, the Prime Minister has said that he is looking forward to working with the crossbench, he recognises he has had a long-standing relationship with a number of us."
