Neringa Narusyte was a passenger in a black Vauxhall Corsa which was in collision with another car on the B9016 Keith to Buckie road in Moray on Wednesday night.
One of the injured girls, aged 14, has life-threatening injuries and was transferred to Glasgow by air ambulance.
The other girls, aged 16 and 17, have serious injuries but are stable.
The four teenagers were passengers in the Corsa which was being driven by a 17-year-old boy.
He and the 42-year-old man driving the other car, a grey Nissan Terrano, suffered minor injuries.
Neringa was a third-year pupil at Buckie High School where the rector, Neil Johnson, described her as a popular girl with a wide circle of friends.
He said: “This is the type of news that all schools dread and it has hit everyone here very hard.
“Staff spoke to all our pupils first thing this morning to break the news to them and, along with members of our chaplaincy team, we held a special assembly for S3 pupils this morning.
“The loss of Neringa is felt by us all but I am confident that the very strong community spirit at Buckie High will help us support each other and deal with this tragedy.
“A support centre has been set up in school by our guidance staff, chaplains and support staff to help pupils and staff who are affected by this tragedy share their feelings and support each other. This will remain open for as long as it is needed.”
Police have appealed for information about the crash which happened near Rye Riggs, Aultmore at 10.38pm on Wednesday.
Road policing sergeant Rob Warnock said: “My thoughts, and that of my officers, are very much with the family and friends of the 14-year-old girl who sadly died in this tragic collision.
“I would appeal to anyone who may have seen the crash or who may have seen either vehicle shortly beforehand and who hasn’t yet spoken with police to do so as a matter of urgency to help us piece together exactly what happened.”