This dissertation studies the pervasive significance of wonder and its corollaries to Persian literary culture between Iran and India, with a particular focus on the Safavid poet Mīrzā Jalāl “Asīr” Shahristānī (b. ca. 1608 – d. ca. 1648). Characterized by complex imagery and syntax and a sustained thematic interest in astonishment (ḥayrat), Asīr’s poetry once enjoyed enormous popularity across Persianate Iran and South Asia as the exemplum of a literary style canonized as khayāl-bandī, though his renown has receded dramatically in the modern period. Through attention to a broad range of texts in Arabic and Persian that circulated around the late-medieval and early modern Islamicate world–including works of philosophy, rhetoric, cosmography, commemoration, and poetry– the main argument advanced in this dissertation is that Asīr’s poetry and its once broad appeal can be best understood through the prism of a “poetics of wonder”, an orientation towards literary language rooted in discourses that valorized complexity, contemplation, silence, mystery, and the cultivation of feelings of awe and astonishment. The dissertation is organized into two parts and four chapters. Part I, titled: Style, Wonder, and Hindustan in Persianate Cultural History, consists of two chapters, both exploring the history of the rhetorically complex school of Persian literature in which Asīr’s poetry is often situated, and its association with Persianate India. In Chapter One, “Locating Style between Iran and India: The Indian Style and its Critics”, I overview and critique the ways in which modern scholars of Persian literature have approached the study of style, and the critical legacy of the so-called “Indian style” or sabk-i hindī in particular, proposing an alternative framework. Through a close reading of Amīr Khusraw’s (d.1325) overlooked rhetorical writings, in Chapter 2, “Inimitable Complexity: Amīr Khusraw’s Poetics of Wonder”, I develop this framework by suggesting that medieval Islamicate attitudes to the emotion of wonder became an especially important element to the structure of thinking and feeling that influenced him and other Persian poets to pursue a complex and more rhetorically wrought literary style. Consisting of two chapters, Part II of the dissertation is titled Jalāl Asīr’s Poetics of Wonder and serves as an extended case study on a poet who falls squarely within the tradition of rhetorically complex Persian poetry, Jalāl “Asīr”. In Chapter Three, “Memorial, Elegy, Mythos: The Canonization of Jalāl Asīr and khayāl-bandī”, I explore how Asīr’s reputation spread from Iran to India (even though he himself never travelled there), through reading a range of commemorative texts. In the final chapter, “The School of Astonishment: Asīr’s Poetics of Wonder and his Interlocutors”, I examine Asīr’s ghazal poetry itself. Through close and comparative readings of his poems, I stress how astonishment and bewilderment were not only central themes of his poetry, but also its main affect, achieved through unusual and innovative uses of grammar, syntax, and imagery. In this way, I argue that astonishment and wonder occupy a central position in Asīr’s poetics as well as the literary style and community of feeling for which he became a figurehead.