Most likely victims are Welsh-speaking girls
Funky Dragon, the children and young people's assembly for Wales, questioned more than 12,000 11 to 18-years-olds, a quarter of them Welsh speakers, and found anyone standing out from the crowd risked being picked on.
In its report covering children's rights, 46 per cent of respondents said they had been bullied. However, it didn't define what bullying was.
"We recognise the experience is personal to each individual," concludes the report.
The Funky Dragon's steering committee presented the report to Assembly members and Assembly government officials at a dinner in Cardiff on Wednesday.
It reveals that 42 per cent questioned didn't know anti-bullying guidance existed in their school and that many were dissatisfied with how policies were carried out.
More than half - 55 per cent - didn't find personal and social education helpful. One negative effect of bullying on education revealed is that 56 per cent of those singled out didn't take part in after-school activities.
Just over 30 per cent felt vulnerable on school transport, especially young males.
The report recommends anti-bullying policies be extended to cover school transport. In one case, bullies even descended on a boy's house and began banging on the windows.