Emergency services were called to Loch Insh Outdoor Centre at Kincraig near Aviemore in the Scottish Highlands at about 2.30am, where Ruby Dench was found unconscious after feeling unwell.
Efforts were made to resuscitate the P7 pupil, but she was later pronounced dead at Raigmore Hospital, Inverness.
Head teacher of Whiteabbey Primary, Peter Wright, said everyone connected with the school was devastated by what had happened.
She really did bring a brightness to every day in the school and clearly at this time our thoughts are with her parents, brother and wider family.
Peter Wright, Whiteabbey PS
It is understood that some other children had been feeling unwell and were examined by a doctor as a precaution. None of them gave any cause for concern.
A total of 58 pupils and six adults made the journey to Scotland, where they had been since Monday. They have cut short the trip and returned home by boat on Wednesday evening.
All parents have been informed and reassured that there is no cause for wider concern.
"Over the coming days and weeks, there will be support for children and indeed for staff," Mr Wright added.
A spokeswoman from Police Scotland said that the 11-year-old's death was being treated as "unexplained" and that a post mortem will be carried out.
Education Minister John O'Dowd said his thoughts are with the girl's family.
"It was with deep sadness and regret that I heard about the death of a pupil from Whiteabbey Primary School while on a school trip," he said.
"My thoughts are with the child's family and indeed the pupils, teachers and wider school community at what is a profoundly distressing time.
"The North Eastern Education and Library Board stands ready to provide support, including access to counselling, to the pupils and teachers in the days and weeks ahead."