Bodies Atomic: Lucretian Poetics in the Renaissance reveals a forgotten atomist genealogy at the heart of the lyric tradition. Today, Lucretius is well known as a source of materialist thinking in the Renaissance, but I argue that Renaissance poets read De rerum natura (DRN) as a meditation on the imagination, generating a line of atomist thought in and about verse. In Lucretius's versification of the atom - an invisible body situated at the tender intersection of the imaginary and the corporeal - Renaissance readers discovered a poetics that theorized how the resources of verse could elucidate material reality. On the one hand, Lucretian poetics helped them articulate poetry's purchase on material conditions, from patronage networks to politics. On the other, DRN asserted an intimate connection between poetry and natural philosophy, offering a vision of how poetry might constitute a natural philosophical method, even at a time when the rise of empirical scientific methodologies downgraded the capacity of the human imagination to conceive of and explain natural phenomena. Looking to DRN for theories of the imagination rather than matter, I reconsider what "materialism" means in the context of early modernity, and give a very different answer to the question of what made Lucretius important to the Renaissance. Moving outwards from a reading of Ovid and Petrarch's rarely acknowledged debt to Lucretius, the four chapters cover a wide range of Renaissance lyric, touching on such important figures as Petrarch, Pierre de Ronsard, Remy Belleau, John Donne, and Margaret Cavendish. The first two chapters argue that sixteenth-century French Pléiade poets recast Petrarchism in Lucretian terms, reimagining the Petrarchan poet's tears and sighs as atoms. Under the influence of Lucretius, Petrarchism became a tool for asserting the bond between poetry and matter, particularly for figuring poetic discourse as politically effective, an important concern for poets writing during the Wars of Religion. Chapter One, "A Replica of Love," looks at how Ronsard's Sonnets pour Hélène (1578) and Discours des misères de ce temps (1562) meld the tropes of love poetry with historical and political content. The second chapter, "Natural Resources," engages a lesser-known Pléiade poet, Remy Belleau, to argue that Belleau's lapidary collection, the Pierres précieuses (1576), adapts Lucretius's account of magnetism to figure poetic innovation as the driving force behind France's consolidation of political might, as well as the revivification of her cultural and natural resources. The third and fourth chapters turn to seventeenth-century England to demonstrate the persistence of Lucretian poetics in a period more commonly associated with the birth of modern scientific atomism. "All in You Contracted Is," Chapter Three, argues that John Donne uses atomist cosmology to envision and construct the networks in which his poems circulated. Contrary to common arguments that see in Donne's atomist imagery a hostile reaction to contemporary scientific innovations, I show that atomism is immensely productive for Donne as a way of envisioning literary networks. In my final chapter, "Poems and Fancies," I demonstrate that Margaret Cavendish's early atomist verse develops a Lucretian poetics that leads, in her later natural philosophical writings, to an imaginative epistemology in which fancy and the imagination, not experiment, are the proper tools for natural inquiry. By exposing the philosophical and literary stakes behind Cavendish's feminization of atomist cosmology and imaginative fancy, this chapter directly takes up the issues of gender and agency that run through the first three chapters.