Transport police were called to Kirknewton station in West Lothian at 10.05am on Monday following reports of a woman making threats to staff and passengers.
The 43-year-old was removed from the train and the service was delayed.
A spokesman for British Transport Police confirmed the woman had been arrested “on suspicion of assaulting a police officer”.
On its way from Glasgow to Edinburgh via Shotts, the service resumed shortly after the woman was removed from the train.