This essay features a comparative study of the aesthetics represented by the Greco-Roman critic Longinus and the Chinese Taoist philosopher Zhuangzi through what I would call the cosmic sublime. Both Longinus and Zhuangzi, I propose, articulate an aesthetic ideal of the cosmic sublime, by which I mean the grandeur captured by a cosmic perspective or obtained from contemplating phenomena of a planetary scale, as well as the emotions associated with experience of the sublime. And both seek to theorize the sublime by positing the great-small and subject-object distinction. While concurring to the importance of great natures in producing and appreciating sublime images, the two thinkers diverge with regard to the relation of the subject and object of aesthetic judgment. Where Longinus presages Kant in emphasizing the preeminence of the judging mind in comprehending cosmic phenomena, Zhuangzi asserts the merging of the aesthetic subject with the primal simplicity, a claim that anticipates Hölderlin and Nietzsche’s call to identify with the Dionysian One. As an aesthetic category, the cosmic sublime provides a vantage point from which to view how the human mind confronts and conceptualizes grandeur of an infinite dimension. As a comparative lens, the cosmic sublime helps reveal not only a new aesthetic ideal but also a distinctive Chinese aesthetics analogous to the Western sublime tradition.