The man was pronounced dead at the scene at King Edward Road, Thorne, early on Sunday evening, after members of the public had reported concerns for his safety.
The Yorkshire Air Ambulance was sent to the town to try to save him.
A South Yorkshire Police spokesman said: “Emergency services were called to King Edward Road, Thorne at 5.15pm yesterday (Sunday 18 April) following reports of concern for the safety of a man.
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“Despite attempts at CPR, the man was sadly pronounced dead at the scene by the ambulance service.
“His death is not being treated as suspicious and a file has been prepared for the coroner."
A spokesman for the Yorkshire Ambulance Service added: “The air ambulance was part of an emergency response to a medical incident in the Thorne area.”