Jeni Larmour is one of four young people who died within hours of each other after apparently taking illegal drugs at the weekend.
The teenager died on Saturday morning and a second woman was found unresponsive in the same university accommodation on Sunday afternoon.
The university said the teenagers had been in the city for less than 48 hours.
The Royal School in County Armagh posted a message on its Facebook page, remembering the deputy head girl.
"Jeni came to the Royal School in Year 8 and in the years that followed was a model pupil, exemplifying many of the values which this school seeks to promote," it said.
"Her outstanding qualities as a pupil were recognised in her final year when she was appointed Deputy Head Girl, a role she carried out to a very high standard.
"It was Jeni's ambition to attend the Royal School and she wasted none of the opportunities offered to her here. Jeni threw herself enthusiastically into school life."
The statement goes on to describe how Ms Larmour was "blessed with a beautiful singing voice" and was a member of the Chamber Choir.
She had also travelled to New Delhi in late 2019 as part of a charity project.
The tribute said: "We have no doubt, that given her academic ability and personality, Jeni had a bright future ahead of her and we are saddened that has been so suddenly cut short.
"We extend to her many friends, her family, brother, and parents our sincerest sympathy at this tragic time and assure them of our prayers and practical support."
An 18-year-old, who was not a student, in nearby Washington, Tyne and Wear, and a 21-year-old from Northumbria University living in Newcastle also died over the weekend, after they apparently took MDMA separately.
Northumbria Police said they have arrested a total of 10 people and a large investigation is under way, including using drug dogs to search student accommodation.
Newcastle University's vice-chancellor Professor Chris Day said freshers' week had not been a factor in either of the young students' deaths.
During a virtual news conference, he said: "This happened in the first 48 hours, freshers' week had only just started to kick off."
Prof Day has written to every student warning them about the two tragedies.
Chief Inspector Steve Wykes urged anyone with illegal drugs to safely dispose of them.
Mr Wykes said: "This weekend, we have seen the tragic loss of four young lives and our thoughts continue to be with the family and friends of those who have sadly died."
He said it was too early to say if the drugs were part of two larger deadly batches.
"Illegal drugs are never safe and the danger that they pose cannot be underestimated," he told reporters.