The collision happened on the B9102 near the Dandaleith junction north of Craigellachie in Aberdeenshire at 9.25am, police said.
Ambulance and police attended the scene where the cyclist had been fatally injured.
The driver of the Vauxhall Corsa was not hurt.
Road closures have been put in place while an investigation is carried out.
No further details about the cyclist have been released.
Meanwhile, a woman has been taken to hospital after a crash which trapped four people in a car.
Emergency services were called to Temple of Fiddes on the A90, five miles south of Stonehaven in Aberdeenshire at 2.40pm.
There were four people trapped in a white Seat Ibiza on the southbound carriageway, police said.
Three people were injured and one woman was taken to Aberdeen Royal Infirmary (ARI).
"One vehicle was involved and four people trapped within the vehicle. Three were injured, two were walking wounded and one female has been taken to ARI," a police spokesman said.
The road was partially closed for less than two hours and has been fully reopened.
Anyone with information about either of these incidents has been asked to contact police by calling 101.