Revellers erupted in cheers amid a confetti-filled celebration in New York's Times Square to welcome in the new year, part of a series of star-studded parties and glittering fireworks displays around the world to usher in 2012.
From New Zealand to New York, the world eagerly welcomed a new year and hoped for a better future, saying goodbye to a year of hurricanes, tsunamis and economic turmoil that many would rather forget.
In New York, hundreds of thousands gathered on Times Square to witness a crystal ball with more than 30,000 lights -- and decorated with 3,000 Waterford Crystal triangles -- descend at midnight. Lady Gaga and Mayor Michael Bloomberg led the crowd in the final-minute countdown.
Revellers in Australia, Asia, Europe and the South Pacific island nation of Samoa, which jumped across the international dateline to be first to celebrate, welcomed 2012 with pyrotechnic displays.
Fireworks soared and sparked over Moscow's Red Square, crowds on Paris's Champs-Elysees boulevard popped champagne corks at midnight.
But many approached the new year with more relief than joy, as people battered by weather disasters, joblessness and economic uncertainty hoped the stroke of midnight would change their fortunes.
The first worldwide celebrations started in the island nation of Samoa, which hopped across the international date line at midnight last Thursday, skipping Friday and moving instantly to Saturday.
Samoa and the neighbouring nation of Tokelau lie near the dateline that zigzags vertically through the Pacific Ocean; both sets of islands decided to realign themselves this year from the Americas side of the line to the Asia side to be more in tune with key trading partners.
In Sydney, more than 1.5 million people watched the shimmering pyrotechnic display designed around the theme 'Time to Dream'. In London, some 250,000 people gathered to listen to Big Ben chime at the stroke of midnight.
In Brazil, heavy rains did not halt parties as upward of two million people gathered on Copacabana beach in Rio de Janeiro and nearly as many on a main avenue in Sao Paulo.