It is understood the man in question is a worker on the crossing and that he was taken ill shortly after arriving for his shift.
Transport Scotland confirmed an ambulance attended and had taken a man to hospital.
A spokesman said: “Unfortunately, one of our colleagues suddenly took ill this morning just prior to starting his morning shift.
“Co-workers immediately provided first aid prior to the prompt arrival of the emergency services.
“With great sadness, we have learned that the person in question has died.
“On behalf of everyone connected to the project, we extend our deepest sympathy to his family and friends at this tragic time.”
The incident is understood to be unconnected to work activities.
A Police Scotland spokesperson said: “Police Scotland were contacted after a 57-year-old man took unwell on the Queenferry Crossing around 9am on Monday 6th February.
“He was taken to Victoria Hospital, Kirkcaldy where he later passed away.”