All 29 girls who signed up to the Facebook page were sent home
Dozens of girls were suspended from a C of E school for setting up a defamatory Facebook site about a teacher.
Some 29 pupils aged between 11 and 18 at Grey Coat Hospital girls' school in Westminster signed up to the webpage, which they called The Hate Society.
They were suspended from two to 15 days and most will return on Tuesday.
Head Teacher Rachel Allard said the decision was designed "to send a strong message to those responsible that we do not tolerate such behaviour."
Code of conduct
She said the girls had posted a series of deeply insulting comments on Facebook about a member of staff. The site has been taken down.
Ms Allard added: "The vast majority of parents who have been to see me about this incident are supportive of the school and understand why we have taken firm disciplinary action."
The comprehensive school traces its beginnings to 1698 when it was founded by local churchgoers to educate the poor of the parish and make them "loyal citizens, useful workers and solid Christians".
Pupils are expected to follow a code of conduct which states they should "avoid behaving in a way which is threatening, rude, hurtful or humiliating".