An estimated 400,000 people, both local and from further afield, brought in the new year with a bang in London.
Before the clock struck midnight, London Mayor Boris Johnson spoke to the crowds via video. He quoted from the film Apocalypse Now to make his point that the financial crisis was not the end of the world.
Partygoers in London had to wrap up warm against the freezing temperatures, which were repeated across the UK.
As temperatures plummeted to minus 2C in Edinburgh, about 1000,000 revellers gathered to take part in one of the most famous new year parties in the world.
The main event of the £250,000 Hogmanay spectacular was the city's street party, set against the dramatic backdrop of Edinburgh Castle and Princes Street Gardens.
Police said the celebrations in Edinburgh had been "safe and successful".
The Edinburgh crowds were entertained by Scottish singer Paolo Nutini and dance act Groove Armada before a huge fireworks display heralded in 2009.
The fireworks were followed by one of the biggest mass renditions of Auld Lang Syne and a light and laser show.