Passengers on the line experienced delays of around one hour while British Transport Police attended a call of a death on the line.
Police were called to the railway close to Huddersfield at about 1.45pm after reports of a casualty on the tracks.
Paramedics also attended but the person as sadly pronounced dead at the scene.
The gender or age of the person has not yet been confirmed.
The death is not being treated as suspicious.
Police say they are working to track down the person's family to inform them.
Delays to rail services may still affect passengers travelling on Thursday afternoon, although the line itself has now reopened as of 4pm.
A spokesman for British Transport Police said: "Shortly after 1.45pm today (29/08) officers from British Transport Police were called to the railway close to Huddersfield, West Yorkshire after reports of a casualty on the tracks.
"Paramedics also attended, however a person was sadly pronounced dead at the scene.
"Officers are now working to identify the person and inform their family.
"This incident is not currently being treated as suspicious and a file will be prepared for the coroner."