Tutagual (Welsh: Tudwal) is thought to have been a ruler of the kingdom of Alt Clut, later known as Strathclyde, a Brittonic kingdom in the Hen Ogledd or "Old North" of Britain.
The Harleian genealogies, Adomnán's Vita Columbae, and the Bonedd Gwŷr y Gogledd indicate that Tutagual was the father of the much better known Rhydderch Hael, who was presumably his successor.
[1] The Harleian genealogies name Tutagual as the son of Clinoch, son of Dumnagual Hen, both of whom were probably his predecessors as king.
[2] Tutagual of Alt Clut may be identified with a tyrannical ruler mentioned as Saint Ninian's contemporary in the 8th-century poem Miracula Nyniae Episcopi and in Ailred of Rievaulx's 12th-century Vita Sancti Niniani; the Miracula calls this king Tuduael and Thuuahel, while Ailred gives the forms Tudwaldus and Tuduvallus.
[1] However, historian Alan MacQuarrie notes that this would conflict with other suggested dates for Ninian's life.