They fear such pages open children to abuse and blacken the reputation of the students' school, The Daily Telegraph reported Friday.
"Send me a message with your secrets and I will put them on here anonymously," says one site, "Penistone Grammar School's Dirtiest Secrets," which has 600 fans.
The site contains crude and explicit messages about students at the school in South Yorkshire.
Similar pages have been found for three other schools in the area.
Geoff Baddock, senior deputy head at Penistone, called the page "appalling" and said he was working with local authorities to have Facebook take down the page.
He said the school was warning students the page "is inappropriate and putting themselves at risk."
A site for Kirk Balk Community College was reported to Facebook minutes after students alerted teachers to its existence. The students discovered the site Monday night.
Facebook removed the page four hours after the school called.
Val Malcolm, the head teacher at Kirk Balk, said Facebook should have acted "within minutes," saying "this is about the health and safety of children who may be foolish and not have thought [about] what they were doing."
The site was taken down because it broke Facebook rules, said a spokesman for the company.