The aim of this essay is to focus on and analyse the romantic aspects of De Stijl theory. It is argued that these romantic aspects have received less detailed analysis than the classicising tendencies within this movement’s underlying theory. The terms ‘classic’ and ‘romantic’, as used within the context of De Stijl theory, will be clarified for the purposes of this analysis. The article focuses on De Stijl theory, as reflected in the writings of the founding members of the movement, with specific reference to artist Piet Mondrian. Examples of De Stijl art and design are mentioned in order to contextualise certain ideas as formulated by Mondrian in particular, but this article does not focus on a discussion of the artworks themselves. Careful analysis of (as argued here) neglected aspects of De Stijl thought, makes a broader, more inclusive contextual interpretation of De Stijl art and design possible. Whilst acknowledging the existence of Western romantic thought and its influence on early twentieth-century abstract painting, this article focuses on a more specifically Eastern romantic notion of monism and antimaterialism as the basis for the formulation of De Stijl abstraction.