Port William (Scottish Gaelic: Cill na Tràghad) 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.

Monreith House, a category A listed Georgian mansion is located 1 mile (1.6 km) east of the village.

The original settlement was known as Killantrae, meaning 'The Church on the Beach' in Gaelic, and was probably founded not long after St Ninian's arrival in nearby Whithorn towards the end of the 4th century.

[3] Killantrae was swept away following the intervention of developer and landlord Sir William Maxwell, 5th Baronet, of Monreith House.

One of the earliest buildings still standing was the corn mill, located on the side of the Killantrae burn to take advantage of the power provided by its water.