In Australia, more than one million people watched a pyrotechnic display centered around Sydney's famous Opera House and Harbour Bridge.
"It's total madness," said German tourist Janna Thomas, who waited in line since 7.30am to secure a prime waterfront location.
Some 90,000 police and security officers were deployed around France including along Champs-Elysees Avenue, where large crowds took in a multidimensional light show projected onto the Arc de Triomphe showcasing the history of Paris and sports on the menu for the 2024 Summer Olympics in the city.
Large crowds took in a multidimensional New Year light show projected onto the Arc de Triomphe. (AP PHOTO)
In New York, people lined up early to nab a spot in Times Square for the midnight ball drop. Officials and party organisers said they were prepared to keep tens of thousands of revellers safe in the heart of Manhattan, as the city has seen near-daily protests sparked by the Israel-Hamas war.
Stunning fireworks displays bloomed at iconic locations like the Acropolis in Athens, reflected in the sleek glass walls of the world's tallest building, the Burj Khalifa in Dubai, and accompanied a collective cheer filling the air in Nairobi.
China celebrated relatively quietly, with most major cities banning fireworks over safety and pollution concerns. Still, people gathered and performers danced in colourful costumes in Beijing, while a crowd released wish balloons in Chongqing.
During his New Year address, President Xi Jinping said the country would focus on building momentum for economic recovery in 2024 and pledged China would "surely be reunified" with Taiwan.
The mood was upbeat in Taiwan's capital Taipei as revellers gathered for a fireworks show at the bamboo-shaped Taipei 101 skyscraper and at concerts and other events citywide.
In India, thousands of revellers from the financial hub of Mumbai watched the sun set over the Arabian Sea. Fireworks in New Delhi raised concerns that the capital, already infamous for its poor air quality, would be blanketed by a toxic haze on the first morning of the new year.
Across Japan, people gathered at temples such as the Tsukiji Temple in Tokyo, where visitors were given free hot milk and corn soup as they stood in line to strike a massive bell.
At the Vatican, Pope Francis recalled 2023 as a year marked by wartime suffering.
During his traditional Sunday blessing from a window overlooking St. Peter's Square, he offered prayers for "the tormented Ukrainian people and the Palestinian and Israeli populations, the Sudanese people and many others".
"At the end of the year, we will have the courage to ask ourselves how many human lives have been shattered by armed conflict, how many dead and how much destruction, how much suffering, how much poverty," the pontiff said.
The ancient Parthenon temple in Athens was among the world landmarks lit up by New Year fireworks. (AP PHOTO)
In Russia, the country's military actions in Ukraine overshadowed end-of-year celebrations, with the usual fireworks and concert on Moscow's Red Square cancelled, as they were last year.
After shelling in the Russian border city of Belgorod Saturday killed 24 people, some local authorities across the country also cancelled their firework displays, including in Vladivostok.
Israeli strikes in the Gaza Strip killed at least 35 people on Sunday, hospital officials said, as fighting raged across the tiny enclave a day after Israeli Prime Minister Benjamin Netanyahu said the war will continue for "many more months", resisting international calls for a ceasefire.
Skyscrapers in Tel Aviv were lit up in yellow to call for the release of hostages held by Palestinian militants in Gaza for more than 80 days.
In the Gaza Strip, displaced Palestinians huddled around fires in a makeshift refugee camp.
Security was also heightened across European cities on Sunday.
German authorities said they detained three more people in connection with a reported threat of a New Year's Eve attack by Islamic extremists on the world-famous Cologne Cathedral.
In Berlin, some 4500 police officers were expected to keep order and avoid riots like those seen a year ago.
