The road was closed for almost two hours while emergency services attended the scene of the incident.
A police Scotland spokesperson said: “We received reports of a one-vehicle crash on the A9 at around 8.10am this morning.
"The incident happened between Dornoch and Golspie.
"A male casualty was airlifted to Raigmore Hospital in Inverness.
"The road reopened again at around 10am."