The 49-year-old victim was trapped underneath the train but was not seriously hurt, a British Transport Police spokesman said.
She was discovered on the tracks underneath the 11:05 ScotRail service from Glasgow to Edinburgh Waverley.
Emergency services, including police, fire crews and ambulances, were called to Livingston South station shortly after 12pm today.
They found the woman was still conscious and able to speak to emergency services at the scene.
The woman was prised free by fire and rescue crews and taken to St John's Hospital in Livingston, where her injuries were not believed to be life-threatening.