The victim has been named locally as 13-year-old Heather Still who died in the tragic incident at Whitecraigs Railway Station.
Emergency services were called around 2pm on Tuesday.
British Transport Police have launched an investigation into the circumstances surrounding the death of the pupil who attended Mearns Castle High School in Newton Mearns, East Renfrewshire.
A police spokesman today said: "We are treating the death as non-suspicious but investigations are ongoing. Specialist trained family liaison officers are helping the girl's family."
Train services through Whitecraigs were disrupted for two hours immediately after the tragedy but returned to normal shortly after 4pm.
Paramedics were called to the railway station but the school pupil was pronounced dead at the scene. Afterwards stunned school friends left tributes on social media sites.
Mearns Castle High school head teacher Dean Smith said they were deeply saddened by the tragic news and the loss of a "bright and popular pupil."
He added: "This is a time of profound sadness for our school community and we are concentrating on providing support to our pupils and staff who are understandably shocked and upset. We ask for privacy for the family and for the school to allow us to make sense of this loss. Our thoughts are with Heather’s family."