Thousands gathered around Hong Kong's Victoria Harbor to watch a 10-minute musical firework display, which included 'shooting stars' fired from rooftops and revelers dancing to 'Auld Lang Syne.'
In the Indonesian capital of Jakarta, over 400 couples participated in a New Year's mass wedding provided for free by authorities.
New Zealand, Australia and the surrounding Pacific Islands were among the first places to ring in 2018 hours earlier.
Nearly 1.5 million people gathered to watch a rainbow fireworks display above Sydney's iconic Harbour Bridge and the opera house, as the country celebrated legalizing gay marriage.
Thousands lined the streets of Auckland, New Zealand's biggest city, for the annual street party and fireworks show above the Sky Tower.
Armed police patrol busy public areas around Westminster as security is stepped up ahead of New Year';s Eve celebrations in London, Britain, Dec. 31, 2017.
In preparation for celebrations in cities around the world, hundreds of thousands of law enforcement, military and security officials are being deployed to keep New Year's Eve revelers safe.
In Australia, one of the first places to ring in the new year, officials were out in full force on the ground, air and sea as part of the largest security operation in the country. Police in Melbourne last month arrested a man for planning to shoot revelers on New Year's Eve.
A member of the New York Police Department';s Counterterrorism Bureau monitors security in Times Square ahead of New Year';s celebrations in Manhattan, Dec. 29, 2017.
In the United States, New York City officials announced they will use two-step screening, snipers, street closures and specially trained dogs to secure Times Square, as an estimated 2 million people gather to watch the annual ball drop at midnight.