Emergency services were called shortly after 7am yesterday with the line between Doncaster and Gainsborough Lea Road closed while police carried out investigation work.
A spokesman for British Transport Police said: “British Transport Police were called to the line near Doncaster at 7.21am yesterday following reports of a casualty on the tracks.
"Paramedics also attended, and sadly a man was pronounced dead at the scene.
"Officers are currently working to establish the full circumstances behind his death.”
It is the latest in a series of railway related tragedies in Doncaster in recent months.
In September, Rossington man Michael Rochford was sentenced to ten months in jail after crashing into a train at Rossington in June.