Dubh Artach (/duː ˈɑːrtɑːx/; Scottish Gaelic: [t̪uh ˈarˠʃt̪əx]) is a remote skerry of basalt rock off the west coast of Scotland lying 18 miles (29 km) west of Colonsay and 15 miles (24 km) south-west of the Ross of Mull. The translation of Dubh Artach is "The Black Rock", artach being a now obsolete Gaelic word for a rock or rocky ground both in Scottish Gaelic and in Irish.
A lighthouse designed by Thomas Stevenson with a tower height of 145 feet (44 m) was erected between 1867 and 1872 with a shore station constructed on the isle of Erraid. The rock is subject to extraordinary sea conditions with waves of 92 feet (28 m) or more being encountered by the keepers. Despite these adverse conditions several men served the light for lengthy periods until it was automated in 1971. Dubh Artach is the official name of the lighthouse, although the skerry itself is also known as Dhu Heartach. Various interpretations have been provided for the original meaning of the Gaelic name, of which "The Black Rock" is the most likely.