London
London rang in the New Year with a triumphant firework display at the London Eye, accompanied by a pop medley which included Ariana Grande's hit One More Time in tribute to the victims of the Manchester Arena bombing in May. The colourful show was followed by a rousing rendition of Auld Lang Syne between strangers and friends alike, all gathered on the banks of the Thames to ring in 2018.
London welcomes 2018 with celebrations over the River Thames #LondonNYE #HappyNewYear #tictocnews pic.twitter.com/QbyJDoIEGJ
— Bloomberg Quicktake (@Quicktake) January 1, 2018
Dublin
Despite RTE's broadcast of the capital's New Year celebrations having its technical troubles, Dublin managed to pull off one of the more creative New Year's shows, with jetpack-equipped performers doing aquatic and aerial stunts above the River Liffey. A host of Irish musical talent from Hudson Taylor to Kodaline soundtracked the celebrations with their respective live performances.
New York
With a burst of confetti and fireworks, throngs of revellers ushered in 2018 in a frigid Times Square as the glittering crystal ball dropped.
It was the second-coldest on record, with the temperature only 10F (minus 12C) in New York at midnight.
Partygoers bundled up in extra layers, wearing warm hats and face masks, dancing and jogging on the spot to ward off the cold.
There was also tighter security than ever after two recent terrorist attacks and a rampaging SUV driver who ploughed into a crowd on the very spot where the party takes place. The event went off with no major problems.
Auld Lang Syne and New York, New York played as the crowds cheered.
The coldest ball drop celebration was in 1917, when it was only 1F (minus 17C).
WATCH: Happy New Year 2018 from New York City! pic.twitter.com/glJZwdW1Eq
— NBC News (@NBCNews) January 1, 2018
Sydney
Fireworks lit up the sky above Sydney Harbour, highlighting the city's new year's celebrations.
The massive fireworks display included a rainbow waterfall cascade of lights and colour flowing off the harbour's bridge to celebrate recently passed legislation legalising gay marriage in Australia.
More than one million people were expected to gather to watch the festivities. Security was tight, but officials said there was no particular alert.
Sydney officials said the event would generate "priceless publicity" for the city. Nearly half the revellers were tourists.
Happy New Year! Wishing you and yours a safe and happy 2018. Photo courtesy of the @cityofsydney #sydneyoperahouse #australia #sydney #nye2018 #fireworks #newyear #2018 pic.twitter.com/LSKyQNXORz
— Sydney Opera House (@SydOperaHouse) December 31, 2017
Las Vegas
Las Vegas police officers surrounded hundreds of thousands of tourists gathered to welcome the new year on the Strip, where just three months earlier 58 people died in the deadliest mass shooting in modern US history.
A roughly eight-minute fireworks display at the top of seven of the city's world-famous casino-hotels started 10 seconds before midnight. Sprays of gold, red and green lit up the sky on time for 2018.
Tourism officials expected 330,000 people to come to Sin City for the festivities on the Las Vegas Strip and central Fremont Street.
Happy New Years Eve from Las Vegas. Amazing view! Thank you https://t.co/dglfj2Lxjc community for being with us! #tothemoon pic.twitter.com/iLJpVUXI59
— BobsRepair (@BobsRepair) January 1, 2018
Tokyo
The Japanese celebrate the New Year in a very different way to us westerners. This year marked the arrival of the Year of the Dog, and the country celebrated in the traditional way of praying for peace and good fortune at neighbourhood Shinto shrines and eating new year's food such as noodles, shrimp and sweet black beans.
Barbecued beef and octopus dumpling stalls were out at Tokyo's Zojoji Temple, where people took turns striking the giant bell 108 times at midnight, an annual practice repeated at other Buddhist temples throughout Japan.
Thousands gathered at Tokyo's famous Shibuya Crossings to count down from ten to zero.
Thousands of people gathered, waiting for New Years’s Countdown at Shibuya Crossings in Tokyo. #tokyo #shibuya #japan #newyearcountdown https://t.co/0wMPhcZ03I pic.twitter.com/T32GnNFsKY
— Nabeel Ahmed (@nabeellahmed) December 31, 2017
Moscow
Not many words are needed to describe Russia's New Years celebrations, when an image like this can do all of the talking.
Happy New Year from #Moscow, Russia 🇷🇺 🎇🎆🍾🎄🇷🇺 We hope 2018 will be a great year for everyone!
📷 @hobopeeba pic.twitter.com/hPww9wSsNj— Russia Beyond (@russiabeyond) December 31, 2017
Vatican
Even the Vatican city had their own celebrations for the end of one year and the beginning of another.
Francis presided at a New Year's Eve prayer service in St Peter's Basilica, a traditional occasion to say thanks in each year's last hours.
Bidding 2017 farewell, Pope Francis decried wars, injustices and environmental decay which he said had "ruined" the year.
Live from the Vatican New Year's Eve! https://t.co/eArVLIALJO pic.twitter.com/F9Aij89bRz
— Sherry Peirce (@ChurchSocialTip) January 1, 2018