Actor Ewan McGregor will open the first children's version of the G8 summit of global leaders next month.
Ewan McGregor also works as a Unicef ambassador
Youngsters from the poorest countries will join children from the richest nations at the forum in Dunblane, Stirlingshire on 3 July.
They will draw up a manifesto and present it to world leaders at the summit in nearby Gleneagles.
The 34-year-old - who is also a Unicef ambassador - said: "Children have a unique perspective on the world."
"I am amazed at their eloquent, articulate and passionate views," he added.
"Many living in other countries have had direct experience of issues such as poverty, education, HIV and Aids and deserve to have their voices heard."
Young people representing Bhutan, Moldova, Yemen, Guinea, Sierra Leone, Cambodia, Lesotho and Bolivia will join children from the UK, France, Italy and Germany at the three-day C8 event.
The five youngsters from the UK are Jamie Brown, 17, from Dennistoun, Glasgow; Rachel Parker, 15, from Annan, Dumfries-shire; Laura Calvert, 17, from Bangor, County Down; Saranda Hajdari, 15, from Liverpool; and Jon Hudson, 18, from Birmingham.