Corpus Christi Catholic College in Leeds opened as normal on Tuesday morning with a prayer service attended by hundreds following the death of Anne Maguire who was stabbed to death on Monday.
Pupils, teachers and parents attended the service to pay their respects to the 61-year-old Spanish teacher.
Flowers, photographs, cards and other tributes were left on the railings out the gates of the school. Mrs Maguire recently celebrated 40 years of teaching.
The apostolic administrator of the Leeds diocese, Monsignor John Wilson, said the decision to keep the school open was made after “great consideration by all of the important agencies”.
Bringing the community together was also a factor in the decision to open the school.
"Some people would have been at home alone," said Wilson. "And it isn't good for people to be on their own at times like these."
He also referred to the “groundswell of support” from the UK and abroad about the tragedy.
British police arrested a 15-year-old male pupil after the rare attack on educational staff.
Mrs Maguire suffered multiple stab wounds in the Monday incident which was witnessed by other children at the school in Leeds, northern England.
When news broke of the tragedy Prime Minister David Cameron was among those offering their condolences.
"My thoughts are with the family of Anne Maguire, as well as the staff and pupils of Corpus Christi school, where she was stabbed to death," he said.
Police said teachers at the school captured the suspect at the scene and held him until officers arrived.
"There were a number of stab wounds to the lady in question," said Chief Superintendent Paul Money of West Yorkshire Police.
Violence at British schools has risen in recent years, and there has been growing concern over knife attacks involving teenagers.
But fatal attacks on teachers are extremely rare.
Maguire's death is believed to be the first of its kind since 1995, when London headmaster Philip Lawrence was stabbed to death outside the gates of his school as he went to help a pupil.