John Findlay, 44, took legal action against Aberlour House School, which was was a preparatory establishment Gordonstoun in Morayshire, Many Aberlour pupils went on to attend Gordonstoun, where generations of the British royal family were educated.
Mr Findlay was just 12 in 1990 when a teacher came to his room and drugged and sexually abused him after he had sought help for an injury.
He remained fully conscious during the attack – which was photographed by the teacher – but he was unable to move or speak.
Mr Findlay – who revealed his harrowing ordeal while giving evidence to the Scottish Child Abuse Inquiry last year – said his victory against Aberlour was “an important admission of liability”, which would “act as a warning to institutions tempted to cover up for abusers in their midst”.
He added: “I hope it also shows other victims that it is still possible to stand up and be counted many years later.
“It is well recognised that many children who have suffered abuse hide their experiences until they can no longer conceal their true feelings. No-one should have to suffer in silence.”
Mr Findlay, who has suffered clinically severe post-traumatic stress disorder, depression and anxiety since the abuse, spent years pursuing his claim against Aberlour House.
He thanked Thorntons Solicitors for their “unswerving support and determination to bring forward my claim”.
He added: “I hope my case reassures people that there is light at the end at the tunnel and it gives others confidence to speak out.”
Mr Findlay told the abuse inquiry that the teacher gave him medicine before abusing him, and described how he was “horrendously conscious” but unable to stop the attack.
He later told his parents, who contacted Aberlour’s headmaster.
They were told the teacher – who is now dead – would never work at a school again, andy decided not to press charges, although he said his parents later regretted not going to the police.
Mr Findlay became determined to seek justice after learning his abuser went on to teach elsewhere and abused more victims.
Thorntons began pursuing the case against Aberlour House for Mr Findlay in 2018.
Personal injury solicitor Danny McGinn, who led the claim, said: “Mr Findlay has lived with severe psychological injuries because of what happened to him, affecting his life in so many ways.
“His settlement will allow him to get the specialist help that he needs and that will make a huge difference to his life.
“Mr Findlay’s success shows that the passage of time need not be a barrier to justice. Changes to the legal time limit and introduction of the Redress scheme have made it possible for survivors to pursue claims even after many years.
“With these changes, and with the examples of brave people like Mr Findlay, I expect that we will see more survivors coming forward to confront those responsible.”
When the Scottish Child Abuse Inquiry was first announced, Aberlour’s Chief Executive SallyAnn Kelly said: “To those who suffered abuse while under the care of Aberlour, we reiterate our unreserved apology.”