Muslim, Jewish, Christian, Sikh and black children were among those who contacted the NSPCC helpline about the issue and said abuse and negative stereotyping was so cruel some had self-harmed while many said they wished they could change who they are.
The charity has handled 2,500 counselling sessions in the last three years while centres in Glasgow and Aberdeen have dealt with 159 calls on the subject from children in the last year.
In the two weeks following the Manchester Arena attack in May, ChildLine held nearly 300 counselling sessions across the UK with children concerned about terrorism.
The number of calls after the Westminster attack in March almost doubled to 128.
Many concerned about bullying said they endured constant name-calling and felt threatened. Some young Muslim girls told the helpline they had been victimised when they wore a hijab or headscarf.
One 15-year-old girl told ChildLine: “The boys in my class are always calling me a ‘terrorist’ but my teachers do nothing about it.
“It makes me so angry and upset that I’ve started to cut myself because it numbs the pain.”
A boy, aged 12, said: “I’m upset because people are making racist comments to me today and talking about the Manchester attack. It’s annoying and unfair because I have nothing to do with the attack.”
ChildLine president and founder Dame Esther Rantzen said: “When these events happen, we adults are so often overwhelmed with horror we sometimes forget about the children watching too.
“ChildLine is in a unique position to be able to hear from children who may be ignored or overlooked when there are major events, like terror attacks.
“It is crucial adults are aware of this issue and protect those who may be targeted.”
Joanna Barrett, acting national head of NSPCC Scotland, said: “No child should be targeted because of their race or faith and we cannot allow prejudice to make children feel ashamed of who they are.
“It takes huge courage for a child to speak up about this issue and they must be encouraged to speak up if they are being targeted.
“Some children don’t understand how painful and damaging their words can be, so adults must not turn a blind eye if they see young people turning on one another.
“We must defend those who are being targeted and explain to those who are bullying others why their actions are harmful and wrong.”
• Any child worried about bullying can call ChildLine on 0800 11 11. Adults concerned about a child can call the NSPCC helpline on 0808 800 5000.