Penninghame is a coastal parish, which lies in Dumfries and Galloway Council Area, some 3 miles (5 km) west of Newton Stewart and 19 miles (31 km) east of Stranraer in Dumfries and Galloway.
It is located in the old county of Wigtownshire, which disappeared following the Local Government (Scotland) Act 1974.
The parish has an area of 139.2 sq. km (53.7 sq. miles) and includes the settlement of Newton Stewart. Penninghame has 5 neighbouring parishes; namely Colmonell, Kirkcowan, Kirkinner, Minnigaff and Wigtown.