Yuan Buddhism is a particular variant of Theravada Buddhism that prevails among the Tai-speaking people of the upper Mekong region. A salient feature of Yuan Buddhism is belief in ‘holy men’ who gain renown for their charismatic attributes and construction of religious monuments. I argue in this article that the modern ‘holy man’ tradition, initiated by the forest monk Khruba Siwichai, is a form of religious revivalism that combines the bodhisattva ideal with sacral kingship. This form of revivalism condemns the modern state for its failure to uphold Buddhist morality, resists state control and fosters visions of utopian Buddhist realms.