The 33-year-old man was riding along the A87 near Loch Ainort on Skye.
Emergency services were called to the scene shortly after 9.30am today.
Police Scotland said: "Despite efforts at the scene to administer medical treatment, the single 33-year-old male rider died from injuries sustained.
"Police investigators are currently in attendance and the road will be closed for examinations to take place and a diversion is in place for cars only."
No other vehicles were involved in the crash, police said.