Officers responded to the scene at 8:50 pm with members of the Kincardine Fire & Bruce County EMS and found a pick-up truck and a bicycle were involved.
The cyclist was taken to local hospital where they were pronounced deceased.
Members of the OPP Traffic Incident Management and Enforcement Team are assisting the South Bruce OPP with this investigation.
Highway 21 was closed between Concession 7 & 9 for the protection of emergency responders.
The investigation is in the early stages.
Anyone with information on the incident is asked to contact the South Bruce OPP or anonymously to Crime Stoppers.