The Duke of Cambridge and Prince Harry will present a group of young people from across the world with a new award established in memory of their mother.
The 20 recipients will receive the Legacy Award recognising their efforts at creating positive social change in their communities and countries.
The Diana Award announced it had created the honour at the start of the year, which will see the 20th anniversary of the death of Diana, Princess of Wales commemorated.
The charity was established to promote Diana's belief in the positive power of young people.
It runs a number of programmes, from its anti-bullying and mentoring initiatives to its flagship Diana Award scheme, which recognises youngsters who create positive social change.
Those receiving the Legacy Award have demonstrated qualities of kindness, compassion and service and Diana's sons will meet with the winners to hear their stories during the event in central London.
The winners will have access to a unique development programme which will provide them with the opportunity to enhance their skills in four key areas; leadership, community development, social entrepreneurship and technology for good.
All the Legacy Award winners, who come from the UK, USA, Canada, India, Belize and the United Arab Emirates, have had a major impact on society.
Tessy Ojo, the Diana Award's chief executive, said: "This is a landmark event for the Diana Award as we join the Duke of Cambridge and Prince Harry in celebrating the legacy of Diana, Princess of Wales in this 20th anniversary year.
"Today is about two things; celebrating young people for their selfless contribution to society, their courage and bravery, sometimes in the face of adversity and demonstrating to young people that we, as a collective, value them."