Bill Gates will join director Danny Boyle to address a rally demanding the G8 act on world hunger on Saturday 8 June, as David Cameron hosts a summit on nutrition in London.
Thousands are expected to attend the demonstration in Hyde Park, hosted by the lobby group Enough Food For Everyone If, ahead of a G8 meeting of the world's industrial nations in Northern Ireland in 10 days.
Boyle, the artistic director of the London 2012 Olympic Games opening ceremony, said: "Last year at the Olympics we showed what made Britain great. Now tens of thousands of people across the UK are harnessing that spirit, energy and passion in the fight against hunger.
"And it's a fight we have to win. It's staggering that one in eight people around the world go to bed hungry."
Former Archbishop of Canterbury Rowan Williams, actor David Harewood and singer Myleene Klass are also due to appear, while recorded messages from David Beckham and comedian Eddie Izzard will be broadcast to the crowd.
Sally Copley, spokesman for the campaign, said: "The UK public is demanding change because they know it's high time we address both the causes and the consequences of the hunger crisis. It's the silent scandal of our generation and we plan to make enough noise about hunger so that world leaders have to sit up and take action.
"The Hunger Summit and the G8 summit following it must take ambitious action to end hunger. That means clamping down on tax dodging in poor countries, tackling malnutrition, and cracking down on land grabs.
"We can eradicate hunger, but it needs real political leadership to do so. We're demanding action, not words and a lot is riding on what can be delivered in the next 10 days."
The campaign said the rally was one of three key summits being held in the run-up to the G8 meeting.
The prime minister, David Cameron, will co-host a Nutrition for Growth summit with the Brazilian government, bringing together business leaders, scientists, government and civil society together to discuss hunger and examine ways to "end the cycle".
Cameron is to make the issue of hunger and malnutrition a central theme at the G8 summit in Lough Erne.
Speaking ahead of the various rallies, Friends of the Earth food campaigner Kirtana Chandrasekaran said: "The world's wealthiest nations are guzzling the planet's precious food resources by demanding biofuels to power cars and diets heavily dependent on meat - it's these issues the G8 must address if it's serious about tackling hunger."
The G8 summit brings together the leaders of the UK, US, Canada, France, Germany, Italy, Japan and Russia.
Gates, who founded Microsoft, is in the UK to attend the annual meeting of the secretive Bilderberg group of powerful businessmen and political leaders at the Grove Hotel in Watford, Hertfordshire, where other guests include Google executive chairman Eric Schmidt, Amazon boss Jeff Bezos, International Monetary Fund chief Christine Lagarde and former US Secretary of State Henry Kissinger.
Gates, who with his wife now presides over the Bill and Miranda Gates philanthropic foundation, chaired a meeting of national newspaper editors at the Swiss Re "Gherkin" building in London on Friday, after private talks with Cameron in Downing Street.
In an interview with BBC Radio 4, Gates said his three children would inherit only "a tiny, tiny fraction" of his estimated $72.7 billion (£46.7bn) - "enough that they will feel the need to go out and make their own lives," he said
He and his wife had decided to leave 75% of their wealth to the world's poor, he said.
Earlier this year, Forbes magazine ranked Gates the world's richest man. He has consistently been ranked in the top three since 2000.