A letter was sent out this morning notifying parents at King James’s School, in Knaresborough, after the girl died at her home on Saturday.
Headteacher Carl Sugden explained that all year groups had been informed in assemblies and support was being offered by the school.
He wrote: “This morning we heard of the tragic and unexpected death of a Year 11 pupil at the weekend. She died at home and police inform me that her death is not being treated as suspicious.
“Support has been available through our own staff and we have liaised with staff from the local authority including an educational psychologist, to support staff and students. This support will continue to be available beyond today.
“At this difficult time our thoughts are with the family, but we are aware of the need to support all of our students, and particularly those who were close to the student involved, over the coming days.”
Mr Sugden also listed the websites of national bereavement charities that would be able to offer further support, including the Childhood Bereavement Network and Winston’s Wish. He continued: “In situations like this young people react in different ways.
“I am sure that you will be sensitive to how your child reacts and be supportive to whatever he or she is feeling.
“If you are particularly concerned about your child/children then please do not hesitate to contact school.”
A spokesman for North Yorkshire Police said: “Officers attended a report of the sudden death of a 16-year-old girl at an address in Knaresborough on Saturday, March 18.
“There are not believed to be any suspicious circumstances surrounding her death. Her family are receiving support from specially-trained officers at this very difficult time.”