The collection of more than 4,100 testimonies include accounts from girls aged as young as nine.
The youngsters have written personal accounts of “rape culture”, identifying the school or university the alleged perpetrators attended.
Eton, St Paul’s and Latymer Upper School are among those referenced.
But while these and other private schools commonly appear, there are also examples given of unnamed males from state schools and universities.
The testimonies have been published on Everyone’s Invited website and its Instagram account.
Experiences recounted range from being drugged and raped at parties to explicit images being shared over messaging platforms.
'It exists everywhere'
“The testimonies expose rape culture and the scale of sexual violence amongst young people in the UK,” Soma Sara, founder of Everyone’s Invited, told the BBC.
“If we start pointing fingers at certain demographics or singling out individuals or institutions, we risk making these cases seem like anomalies... when really this problem is pervasive, it exists everywhere.”
Everyone had a responsibility to take action to expose and eradicate this culture, she added.
“It is so important that teachers and parents are able to learn how to communicate with their children and talk about these issues,” she said.
At least 35 people claim to have been raped in their testimony. In the accounts where a university or school is named, it is unclear when the incidents took place.
The high master of St Paul’s said she had informed children’s services of the Instagram account.
“The school completely condemns the actions described, and takes this matter extremely seriously,” Sally-Anne Huang said in a letter to alumni. “[We] would always investigate fully matters of this nature brought to our attention.”
No names or details had been provided so the cases had not been reported to the police, she added.
The issue of reporting is raised in some of the testimonies.
“I blamed myself and think a lot of people - especially men, would blame me for getting into the situation in the first place,” one user wrote of not reporting her rape at the age of 17.
“I didn’t feel that there was space to, or I was ashamed and I just felt so alone,” another account said.
“I never said anything to someone of authority because I had no faith in an outcome,” one account which cites Goldsmiths, University of London, said.
A spokesman for the university said it has a dedicated anonymous reporting and support website for victims of sexual violence, harassment or misconduct.
Goldsmiths Students’ Union also runs anti-sexual violence training for students, and is currently running remote Consent Matters training to help educate students on consent and healthy relationships.
'Long way to go'
“Every case of sexual violence is one too many, and universities are committed to becoming safer places to live, work and study,” said a spokesman for Universities UK, which represents UK universities.
“Universities are taking innovative actions to address some of the issues, but there is a long way to go in ending sexual misconduct for good in higher education.”
A spokeswoman for Eton College said it took any specific allegations “extremely seriously” and would report to the relevant authorities “when necessary.”
Eton College is speaking to the founder of the website and looking for ways to work with them in future.
Latymer Upper School, which is one of the most-mentioned schools, said it was “deeply disturbed” by the accounts on the website.
“We have a zero-tolerance approach to behaviours that foster the prevalence of misogyny, sexism, harassment, abuse and assault,” a spokeswoman said, adding all reports of this kind were escalated to police when necessary.
“We take all such issues very seriously and have encouraged anyone affected to come and talk to us directly. We will be listening carefully to them and reflecting on what further steps we should take.”