A casualty on the tracks was reported at the station in Putney High Street just before 5pm yesterday (April 21).
Officers and London Ambulance Service crews attended, however, the person was pronounced dead shortly after.
The incident is not being treated as suspicious, and a file will be prepared for the coroner.
All lines between London Waterloo and Clapham Junction were closed with trains delayed up to 15 minutes.
All services have since returned to normal.
If you feel affected by what has happened and wish to find support, you can contact the Samaritans on 116 123 via phone for a confidential chat.
A spokesperson London Ambulance Service said: “We were called at 4.58pm yesterday (Monday 21 April) to reports of an incident at Putney Railway Station, Putney High Street.
“We sent a number of resources to the scene, including ambulance crews, members of our Hazardous Area Response Team (HART), a paramedic in a fast response car, an incident response officer and London’s Air Ambulance.
“The first of our crews arrived in three minutes.
“Our crews assisted our emergency services partners at the scene. Sadly, despite the best efforts of first responders, a patient died.”
A spokesperson for British Transport Police said: “Officers were called to Putney railway station at around 5pm yesterday (Monday 21 April) following reports of a casualty on the tracks.
“Paramedics also attended, however sadly a person was pronounced dead at the scene.
“The incident is not being treated as suspicious, and a file will be prepared for the coroner.”
