Run (died c. 878) was probably a ruler of Alt Clut (modern Dumbarton Rock, Scotland) and Strathclyde (the "Clyde Valley"), a Brythonic kingdom in the Hen Ogledd or "Old North" of Britain. The dates of his reign are uncertain, but he probably ruled from the death of his father Artgal in 872 until around 878, when his son Eochaid ascended the throne.