The woman was crossing the tracks between two platforms when she was struck by an Intercity train travelling from Zurich to Geneva on Sunday at 12.15pm, cantonal police said in a news release.
Despite warning sounds and emergency braking, “the collision could not be avoided and the victim was caught between the train and the edge of the platform”, police said.
Customers at the train station restaurant heard the collision and rushed to help the woman, who was still alive, the force said.
“She unfortunately died from her injuries when police and an ambulance arrived.”
The Intercity train does not stop at Romont, a town of 4,600 known for its medieval castle and fortifications, where about a third of the population is foreign.
Police said they were pursuing investigations to formally identify the woman, whose age was not given.
Anyone who saw the accident is asked to contact the Fribourg cantonal police on 026 305 17 17.