This paper defines constitutional ethnography as the cultural study of constitutionalism through its symbolic representations. By focusing on the materiality of constitutionalism as embodied in various state ceremonies such as ceremonies of “royal octroy” (constitution-granting ceremonies) as well as in state monuments honouring the Constitution, it strives to offer an ethnography of a polity’s constitutional identity. In this paper, I argue that in Thailand, Westernized Hindu-Buddhist state ceremonies and monuments using Westernized Hindu-Buddhist symbolism represent the Thai monarch as the ultimate law-giver holding permanent “constituent power” and therefore yielding extra-constitutional customary powers pre-existing the Constitution. This representation, in turn, informs Thai constitutional identity as defined incrementally by courts and jurists since the early twentieth century, which in turn informs present Thai constitutional interpretation. Therefore, this paper argues that the study of state ceremonies can be a useful entry point into the analysis of a “constitutional culture” shaping modes of constitutional interpretation.