The Dornoch Firth (Scottish Gaelic: Caolas Dhòrnaich, ) is a firth on the east coast of Highland, in northern Scotland. It forms part of the boundary between Ross and Cromarty, to the south, and Sutherland, to the north.
Together with Loch Fleet it is a designated as a Special Protection Area (SPA) for wildlife conservation purposes. Additionally, together with Morrich More, it has the designation of Special Area of Conservation.
The total SPA hosts significant populations of the following birds:
- Breeding season: Osprey Pandion haliaetus
- Overwintering: Bar-tailed Godwit Limosa lapponica, Greylag Goose Anser anser, Wigeon Anas penelope, Curlew Numenius arquata, Dunlin Calidris alpina alpina, Oystercatcher Haematopus ostralegus and Teal Anas crecca.
In 1991 the firth was bridged, the new Dornoch Bridge providing a shorter route on the A9 road between Inverness and Thurso; until then traffic had to go by way of Bonar Bridge at the head of the inlet.
On 16 August 1809 the firth was the scene of the Meikle Ferry disaster when an over-laden ferryboat sank with the loss of 99 lives.