Olympic champion Denise Lewis, fashion designers Sir Paul Smith and Dame Vivienne Westwood and entrepreneur Sir Richard Branson have been drafted in as ambassadors to bolster Britain's image abroad.
They top a string of senior figures in sport, fashion, film and music who have been brought on board to support the government's GREAT campaign which aims to give a £1 billion boost to business.
The initiative will be launched across 17 key cities, including LA, Tokyo, Beijing and Sydney, with events including a show in Rio during which images of Britain will be beamed onto Sugarloaf Mountain.
Culture Secretary Jeremy Hunt said: "2012 - with the Olympics and Queen's Diamond Jubilee - will be one of the most exciting and momentous years in this country's magnificent history.
"We must not waste the once in a lifetime opportunity we have been given to showcase to the world all that is great about Britain.
"The GREAT campaign is rousing and inspirational. It will take our message right around the world - Britain is the place to visit, study and invest in right now."
The government aims to deliver 4.6 million visitors to Britain over the next four years, generating tourist spending of £2.3 billion and creating almost 60,000 new job opportunities.
Its GREAT campaign focuses on areas of "UK excellence" including heritage, culture, the countryside, sport, shopping, music, entrepreneurship and technology.
London City Airport, and airports within the BAA Group, will be the first to use the campaign to welcome visitors to Britain this year.
A number of UK companies and organisations - including Burberry, Mulberry, Universal Music, McLaren, the Premier League, the London Stock Exchange and Land Rover Jaguar - have been announced as supporters.
They are joined by others such as British Airways, Virgin, Space NK, Coutts, BAFTA, BT and the National Grid, along with Facebook UK, Google UK, James Bond film-makers EON Productions and Sony Pictures.
The countries targeted are: Brazil, China (including Hong Kong), USA, France, Germany, Japan, Australia, India, Canada.
The key cities are: Tokyo, Hong Kong, Shanghai, Beijing, Guangzhou, Los Angeles, New York, Rio de Janeiro, Sao Paolo, New Delhi, Mumbai, Paris, Toronto, Vancouver, Berlin, Sydney, Melbourne.