Sydney and Hong Kong put on stunning fireworks displays in a spectacular welcome to the New Year, among the first in a wave of celebrations for billions around the world.
An earlier thunderstorm did not dampen the spirits of revellers who camped out at vantage points, some since the morning.
To mark the international year of indigenous languages in 2019, the harbour also hosted a ceremony celebrating Aboriginal heritage that included animations projected onto the bridge's pylons.
In Hong Kong, hundreds of thousands of revellers packed the streets on both sides of the city's Victoria Harbour for a spectacular 10-minute firework show.
Some USD 1.8 million worth of pyrotechnics bathed the city's skyscrapers in a dizzying array of colours accompanied by a score that included Auld Lang Syne sung in Cantonese, Mandarin and English.
Revellers were packed shoulder to shoulder on the densely crowded streets, many festooned with LED lights and sparkly glasses reading "2019".
In the Indonesian capital Jakarta, more than 500 couples tied the knot in a free mass wedding organised by the government, with fireworks shows cancelled out of respect for tsunami victims.
New Year's Eve celebrations were also called off in nearby Banten province, where the disaster struck on 22 December killing more than 400 people.
In Japan, locals flocked to temples to ring in 2019, as US boxing superstar Floyd Mayweather came out of retirement to beat Japanese kickboxer Tenshin Nasukawa in a multi-million-dollar "exhibition" bout outside Tokyo.
The party atmosphere is set to sweep across major cities in Asia, Europe, Africa and the Americas as the clock ticks past midnight.
A strong police presence has become a key element of the festivities, to protect crowds that could be targeted in terror and vehicle attacks.
In Moscow, concerts and light shows will be held across the Russian capital's parks and more than 1,000 ice rinks have been opened for merrymakers.
In Paris, a fireworks display and sound and light show under the theme "fraternity" is set to go ahead on the Champs-Elysees despite plans for further "yellow vest" anti-government protests at the famed avenue.
In Berlin, music lovers will party at a concert at the Brandenburg Gate, but a popular German tradition of setting off fireworks to mark the occasion has been banned in some other cities over safety concerns.
Britain's capital London will usher in the New Year by celebrating its relationship with Europe amid turmoil over the Brexit referendum vote to leave the EU, with the fireworks display at the London Eye to feature music from the continent's artists.
Scottish capital Edinburgh's traditional Hogmanay celebrations will also take on a pro-European theme ahead of the year in which Britain is due to exit the union.
Revellers in Dubai will flock to see fireworks at the world's tallest tower, Burj Khalifa, while another United Arab Emirates city -- Ras al-Khaimah -- will attempt to set the Guinness World Record for "longest fireworks show".
Rio de Janeiro's famous hilltop statue of Christ the Redeemer will be brought to 3D life with special light projections before fireworks illuminate the city's Copacabana beach where around two million revellers, many dressed in white, will party till dawn.
As the world parties, many will also look forward to 2019 and wonder whether the turmoil witnessed during the previous year will spill over into the next.
The political wrangling in Westminster over Brexit was one of the key stories of this year, with a resolution yet to be reached ahead of the scheduled March 29 departure.
US President Donald Trump dominated headlines in 2018 as he ramped up his trade war with China, quit the Iran nuclear deal, moved the American embassy to Jerusalem and met his North Korean counterpart Kim Jong Un in Singapore for a historic summit.
North Korea's commitment to denuclearisation will remain a major political and security issue into next year, as will Syrian President Bashar al-Assad's reassertion of control after Trump's shock military withdrawal announcement.
The war in Yemen, which started in 2014 and has already killed about 10,000 people and left some 20 million at risk of starvation, could take a crucial turn after a ceasefire went into effect in mid-December.
Numerous countries go to the polls in 2019, with key elections in India, Afghanistan, Indonesia, South Africa, Argentina and Australia.
Major sporting events on the calendar include the Rugby World Cup in Japan, the cricket one-day international World Cup in England and the athletics World Championships in Qatar.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)