A child was sexually attacked every 20 minutes last year, according to new figures.
The statistics, released by police, also revealed more than a third of all sex crimes are committed against children, with more than 60 child sex offences reported every day.
Some 23,000 children - more than a fifth of them too young for secondary school - were victims of sex offences in England and Wales during 2010/11.
But fewer than 10% of reported child sex offences ended in someone being sentenced.
The statistics, obtained by the NSPCC in a freedom of information request, cover crimes including rape, incest and child prostitution across all 43 police forces in England and Wales.
Overall, there were 54,982 sex offences last year, including 23,097 against children, the figures showed.
Most of the children (14,819) were aged between 11 and 17, including 8,749 aged 13 to 15. There were 4,973 victims aged 10 and under, including 1,472 who were younger than six.
And six times as many offences were committed against girls (19,790) than boys (3,218).
Britain's biggest force, the Metropolitan Police , received the highest number of reports (3,420), followed by the forces in Thames Valley (1,264) and West Yorkshire (1,170).
Jon Brown, head of the NSPCC's sexual abuse programme, said: "A concentrated effort has to be made if we are to start reducing this distressing level of offences, many of which are committed on extremely young and helpless children.
"When you have a situation where more than 60 children are being sexually abused every day, something is very wrong."
A Government spokeswoman said: "The Government is determined to protect children from sexual abuse and will continue to work across departments, law enforcement, agencies and charities in order to do so."
Meanwhile it has been revealed that Sarah's Law has helped protect more than 200 children from harm in its first year.
Sara Payne , who campaigned for the law to be brought in following the murder of her daughter Sarah, said sex offenders could no longer hide their criminal history and put children at risk.
"If just one child had been kept safe as a result of Sarah's Law, then all the work to see it introduced would have been worth it," she said.
"The fact that it is hundreds of children is wonderful and testament to the fact the scheme is needed."