An emergency call was made at around 7:45p.m on Tuesday, with ambulance crews joined by a doctor and rapid response paramedic.
A spokesperson for the Police Service of Northern Ireland (PSNI) said: "Police attended the scene of a single-vehicle collision involving a quad bike at a property in the Galbally area near Dungannon on Tuesday evening (August 17). "A man in his 20s was pronounced dead at the scene. Enquiries are continuing and the death is not being treated as suspicious at this time."