Port William is a fishing village in the parish of Mochrum in the historical county of Wigtownshire, Dumfries and Galloway, in Scotland with a population of approximately 460.

Mochrum is a coastal civil and Church of Scotland parish situated to the east of Luce Bay on the Machars peninsula and 8 miles (13 km) southwest of Wigtown and in the historical county of Wigtownshire in Galloway, Scotland. It covers 22,000 acres (8,900 ha) and is approximately 10 miles (16 km) in length and 5 miles (8.0 km) in breadth. The parish contains the eponymous village of Mochrum, as well as Port William and the clachan of Elrig.