Dornock is a small coastal parish, which lies in Dumfries and Galloway Council Area, some 3 miles (5 km) east of Annan and 5 miles (8 km) west of Gretna Green in Dumfries and Galloway.
It is located in the old county of Dumfriesshire, which disappeared following the Local Government (Scotland) Act 1974.
The parish has an area of 19.3 sq. km (7.4 sq. miles). Dornock has Annan, Gretna and Kirkpatrick-Fleming as its neighbouring parishes. The boundaries of this parish were modified among significant changes recommended by the Boundary Commissioners after the Local Government (Scotland) Act 1889.