The three-day event brings hundreds of carers from across Scotland, aged eight to 18, together.
The Scottish Government estimates there are 29,000 carers aged under 16 but a charity said research indicates this figure is likely to be much higher.
Young carers look after someone in their family who has an illness or disability, or is affected by mental ill-health or substance abuse.
The Scottish Young Carers Festival opens on Tuesday at an outdoor centre in West Linton in the Borders - the same day as Scottish secondary school pupils’ exam results are announced.
Carers Trust Scotland, who organise the festival, said 86 per cent of those at last year’s event said being a young carer affected them being able to do homework.
The charity said young carers often taken on practical and/or emotional caring responsibilities that would normally be expected of an adult.
Activities at the festival, which is funded by the Scottish Government, include a talent show, silent disco, ceilidh and cinema, as well as dozens of workshops for the 650 people attending.
On the final day, they will have the chance to speak to MSPs and councillors as well as health and education officials.
Florence Burke, Carers Trust’s director for Scotland, said the festival, now in its eighth year, has become a highlight of the summer for many of the young people the charity supports.
“We know many of them will be waiting to hear exam results which could have a bearing on what they do next and wondering how that could affect their caring roles,” she said.
“Young carers don’t often have the opportunity to speak to people like politicians and education officials, people whose decisions can have a big impact on these young carers’ lives.”