Leopardi’s atheism has always been and remains a contentious issue. It has been condemned, denied, and vindicated in equal measure. This volume of essays is the first in English to address the issue directly by examining the development and complex nature of Leopardi’s atheism in the context of the religious beliefs as well as the atheism of his age. There are chapters on the shift in his writings from religious believer to atheist, from an early draft of ‘Christian hymns’ to the later draft of a hymn to Ahriman, god of evil, and on the biblical language Leopardi continued to use in fashioning his first-person voice; on his empiricism, materialism, and relativism, key philosophical themes of significance to religious belief; comparative chapters on Leopardi and Shelley, who was in many ways a kindred spirit, and on Leopardi and the religious revival in Germany through the filtering lens of Madame de Staël; and finally a chapter on Cesare Luporini whose critical studies have been a focus for contemporary debate on Leopardi’s atheism. The first English translation of Leopardi’s satire I nuovi credenti, written in response to the revival of philosophical spiritualism in Naples, appears in an Appendix. Leopardi’s distinct identity as a poet-philosopher has attracted a good deal of attention in Italy although he is virtually ignored outside Italian culture. In the last 20 years he has been increasingly recognised as a key figure of modern western culture, as witnessed by the number of translations of his notebooks, the Zibaldone di pensieri. This study of Leopardi’s atheism appears alongside a new complete English translation of the Zibaldone. It provides, from the perspective of his atheism, an understanding of the complexity and intellectual lucidity of his thought and of the questions all his writings continue to pose for 21st-century readers.