A cyclist in his 40s has died after he was hit by a car at Black Forest Drive in Macedon on Sunday morning.

A Victoria Police spokeswoman said the driver of the car, a 23-year-old Gisborne woman, was in custody.

The cyclist was travelling along Black Forest Drive, near Blackwood Road, when he was struck from behind by a black Hyundai sedan about 9.25am.

"A man in his 40s suffered head, leg and chest injuries," Ambulance Victoria spokesman John Mullen said.