Humberside Police said the motorcyclist was seriously injured in the crash near North Dalton, east Yorkshire, yesterday.
A police spokesperson said: "It happened on an unmarked road between North Dalton and Huggate just before midday.
"The rider of the motorcycle was treated for serious injuries but sadly later died. We’re appealing for witnesses to this incident."
Witnesses should call 101 with the log number 242 of August 24.