Angelina Jolie Pitt will deliver a keynote address on the global refugee crisis as part of a day of special live programming at the BBC.
BBC News will dedicate May 16 to discussing migration and its impact on the world in World On The Move, which will be broadcast from the BBC Radio Theatre and across various BBC shows.
Hollywood star Jolie Pitt is a UNHCR special envoy and will deliver her speech in a session hosted by the Today programme's Mishal Husain. It will be broadcast live on Radio 4, BBC World Service and BBC World News.
Jolie Pitt said: "The debate on the refugee crisis is often polarised and based on fear and misconceptions.
"We need to have a rational discussion that focuses on how we strengthen the systems designed to protect those fleeing war and persecution, while understanding and taking into account the concerns of citizens in host countries.
"Above all, we need to address the conflict and insecurity that are the root causes of the mass movement of refugees."
The actress said she was "looking forward to exploring these issues with the BBC and its global audience, and to a day of discussion in which all sides of the debate can be heard and long-term solutions can be identified and highlighted".
The day is being co-ordinated by the Today programme team and other speakers include former head of MI6 Sir Richard Dearlove.
Presenters John Humphrys and Sarah Montague are set to kickstart the morning with a discussion on reverse migration and the evening will include a live broadcast of the World Tonight from America.
Journalists from the BBC's 30 language services will be contributing and broadcasting from their respective regions.
The BBC's director of news and current affairs, James Harding, said: "If the Today programme ran all day on one story, what new insights would it throw up? We've put together a day of programming involving BBC News and some of Radio 4's biggest programme strands to look at a key story of our time.
"An age of unprecedented mobility is shaping the world we live in for better and for worse.
"From Europe's immigration crisis, the refugee camps of the Middle East, and increased labour mobility from the developing world, the movement of people around the world in response to economic incentive or social unrest is shaping the biggest news stories of the year."
Mr Harding said "only the BBC can bring together people from around the world in a single day, to look at new ideas on a theme we've covered for many years".