Australians turned out in their hundreds of thousands to see in the new year under a midnight sky lit up by fireworks - the harbour bridge an iconic backdrop for many.
In Sydney, crowds were abuzz and at maximum capacity as revellers crammed picnic rugs together across harbour foreshore vantage points.
More than 8.5 tonnes of fireworks went up in smoke alongside 80,000 pyrotechnic effects and the sounds of jubilant cheers.
For some, it was a 17-hour wait after queuing from the early hours of the morning to snag a premium spot.
But it was worth it as the clock struck 12 for the families, friends, world travellers and locals alike who enjoyed the front-row display of pyrotechnics, a smoking ceremony, AI-driven projections onto the harbour bridge and illuminated boats on the water.
Smaller groups were seen dancing on the pylons of the Harbour Bridge while children looked on in wonder.
By 5pm most major vantage points around the foreshore had already reached capacity with the Sydney Opera House full by 11.30am.
Janna Thomas, visiting from Germany, is spending her first New Year's Eve in Sydney and grabbed a spot in the Botanic Gardens.
"It's unbelievable we are here. It feels surreal," she said.
Having waited in line since 7.30am, she described the scene as "total madness".
"It's not so easy to find a good place to sit but the view is incredible."
Sydney Mayor Clover Moore said the city's New Year's Eve festivities provided a $280 million boost to the economy, according to a 2019 study.
"They remind the world that Sydney is a global city for tourism, for business, for culture, for technological creativity and most important, Sydney is an inclusive and diverse city for all our communities," she told reporters on Sunday.
Melbourne was treated to a non-stop and vibrant fireworks display alongside a far-reaching laser show that ignited the city's skyline from across 27 rooftops.
Cheers reverberated through the city after the 12pm show, with hoards of people shuffling out of designated celebration zones after witnessing the three semi-trailer loads of pyrotechnics.
Crowds of more than 400,000 gathered in the city centre to ring in the new year, many vying for a spot at the Docklands' waterfront.
Rose Stafrace, from Mill Park in Melbourne's northeast, had ventured into the city for the fireworks for more than three decades.She thought 2023's New Year's Eve crowd was bigger than the last.
"Every year it gets more and more people," Ms Stafrace told AAP.
Outside Flinders Street Station was choked with people as security officers diverted pedestrian traffic and hoards of revellers flanked either side of the Yarra River.
Melbourne local Jude Esom, who was joined by his partner Tatyanna Herrick and their fourth-month-old son Chiemek Chiazor, was lured to Kings Domain with the promise of Afrobeats.
"I'm from Nigeria, so that's from my country," he told AAP.
"I love it when I come here and see different people, different nationalities.
"It gives me the joy of the Melbourne community."
Similar scenes were happening or about to happen in other state capitals.
Thunderstorms brought torrential rain to the storm-battered Gold Coast during the night but didn't stop an early fireworks display at Surfer's Paradise before that area was hit by a deluge.
