Bob Allan was out for a ride on his bike when he spotted the male nude rambler on a trail between Bessacarr and Rossington near the M18.
Recounting the incident on Monday night, he said: “I was cycling along a fairly well used track - which is secluded in sections.
“I came round a corner and nearly ran into this guy who was starkers, in just his shoes, walking along, rucksack on his back and shorts in his hand.”
Bob, a keen member of Doncaster Rovers’ Fit Rovers project said: “I scared the c*** out of him.
“He covered his modesty with his shorts.
‘A bit cold for that isn’t it?, was all I could muster and got out of there as quick as I could. Only in Doncaster!”
The track is close to Great Yorkshire Way, the M18 motorway and the Amazon warehouses, which are situated alongside the roads.
The secluded path has long been popular with walkers, cyclists, dog walkers and families in Doncaster.
Britain’s best known nude hiker is Stephen Gough, known as the Naked Rambler, an activist who in 2003-04 walked the length of Britain naked but was arrested when he did it again in 2005-06.
Since then, he has spent several periods in prison, having been repeatedly arrested for public nudity.
However, there is no suggestion that the nude hiker spotted in Doncaster is the Naked Rambler.