The incident happened at 9:54 a.m. PT on the Sea to Sky Highway, five kilometres north of Squamish, just past Alice Lake.
BC ambulance confirmed the man was airlifted to hospital. His identity has not been released.
Around 4,000 cyclists were expected to take part in the fourth annual GranFondo race this year.
The 122 kilometre ride takes most riders somewhere between 3½ to 8 hours.