Thomas Carlyle’s novel, Sartor Resartus (1833–1834), has puzzled audiences since its first publication. Constituting one of the most ambitious attempts to put into practice Friedrich Schlegel’s theory of romantic irony in the Anglophone tradition, the novel is curiously resistant to interpretation. This chapter begins by considering how irony in general may be read through humour theory, before addressing the problem of understanding romantic irony in particular. It considers the critical heritage on romantic irony, in particular as represented by the interventions of G.W.F. Hegel and Paul de Man, which has traditionally marginalised the humour in Schlegel’s theory and in romantic irony in general, instead prioritising its ‘serious’ and philosophical qualities. Against this received view, the chapter suggests ways in which Schlegel’s ‘transcendental buffoonery’ is instead conceived of as a humorous experience in which the irony calls the romantic subject into question. The chapter then reads Sartor Resartus as a case study of romantic irony, contextualising the problems inherent in ‘getting’ this kind of humour, both for the Victorian audience who first read the novel and for the modern ones who seek to unpack it.