Officers were called at around 9.40am to reports of a crash involving a car and a white Vespa on the A836 between Thurso and Forss.
The 69-year-old driver of the Vespa was pronounced dead at the scene.
Police Scotland is now appealing for witnesses as it carries out an investigation.
Sergeant Ewan Calder, said: “As our investigation into this incident continues, our thoughts remain very much with the family and friends of the deceased.
“We are appealing to anyone who was in the area and witnessed the crash or saw the white Vespa this morning [Wednesday] to please come forward.
“We are also keen to speak with any motorists who were on the A836 near Thurso and may have potential dashcam footage from the area.”
Anyone with information on the crash has been asked to contact police on 101, quoting incident 0778 of October 6.