The 14-year-old from St Columba's High in Dunfermline, died in the early hours yesterday. A Metropolitan Police spokesman said the death was not believed to be suspicious, but he confirmed that an investigation had been launched to determine the circumstances surrounding the death.
The girl was among a group of 50 pupils and staff who arrived in London on Monday. They were staying at a Travelodge in the King's Cross area. They had spent Tuesday sightseeing, before returning to the hotel in the evening.
A London Ambulance Service spokeswoman said: "We were called just after quarter to two this morning to an incident at an address on King's Cross Road.
"One single responder, two ambulance crews and a duty officer went to the scene and our staff treated a teenage girl and took her as a priority to University College Hospital."
The teenager was pronounced dead shortly after arrival.
Her parents were travelling to London yesterday morning.
Douglas Chapman, Fife education chairman, who was at the school yesterday, said: "It was a very tragic set of circumstances. Everyone at the school is naturally very upset, and our thoughts are with the girl's family."
Mr Chapman added: "The girl's schoolfriends in London with her will be devastated, and we are trying to bring them home as soon as possible."
Donna Manson, area education officer, said: "Our priority at the moment is to make sure that the rest of the school party can be returned home as soon as possible to be with their families."