People around the world are celebrating the start of the New Year, bidding farewell to 2011 and welcoming the start of 2012.
In Australia, more than a million people crowded along the shores of Sydney's harbor, to watch a midnight fireworks extravaganza over Harbour Bridge.
Sydney's firework display is often one of the world's most iconic celebrations. This years display was created to remind Australians that although 2011 has been tough there are better times ahead, with some of the fireworks designed to explode in the shape of a cloud, because "every cloud has a sliver lining".
An hour earlier in New Zealand, thousands of Kiwis took to the streets of Auckland to watch the firework display centered around the city's Sky Tower.
However the capital Wellington was was hit by torrential rain and thunderstorms which forced the cancellation of firework displays.
In Hong Kong a firework display worth £1m lit up the city's glittering skyscrapers, with the towering International Finance Centre the focus.
The first country to welcome 2012 was the Pacific island of Samoa. Revelers on the island nation cheered with extra excitement this year as, having changed their time zone, they became the first rather than the last to great the New Year.
The move is aimed at strengthening trade ties with Australia, New Zealand and Asia.
When the clock stuck midnight on 29 December, Samoa skipped 30 December and moved straight to New Years Eve, 31 December.
The move across the dateline comes 119 years after US traders persuaded Samoa to align its times with the US-controlled American Samoa as well as the US in order to enable trading links with California.
In London officials expect 250,000 to line the banks of the Thames to welcome the New Year with an 11 minute firework display centered around the London Eye.
While in Berlin around a million people are expected to have gathered near the landmark Brandenburg Gate to usher in 2012. At the same time Parisians can expect to watch the Eiffel Tower explode with fireworks.
And in New York celebrating Americans are expected to flood into Time Square to watch the traditional ball drop and a performance from pop superstar Lady Gaga.