Ancient religions can be defined as the religions of Mediterranean antiquity, with important connections to the neighboring Ancient Near East. While different approaches to these religions formed throughout European intellectual history, proper academic theories and methods of their study started to emerge in the nineteenth century, with a proliferation of new approaches beginning with the 1990s. Historical approaches reconstruct the development of religions through time and discuss the problems of such reconstructions. Textual criticism studies manuscript traditions and attempts to reconstruct the original text. Various philological methods developed and used especially in biblical studies include the analysis of written and oral sources behind the text, the examination of editorial processes, and reasoning about the original context of the text. Archaeology studies built structures and artifacts from antiquity, employs a variety of dating methods, connects artifacts to social, economic, and environmental conditions, and explores the size, distribution and interconnectedness of archaeological sites. Texts and artifacts might tell different stories and interpretation is needed to gain information from both types of historical evidence. Literary theory approaches texts as finished artifacts instead of looking at the history behind the text. Text-centered approaches include rhetorical, narrative, and typological analysis. Reader-response criticism emphasizes the role of the reader in establishing the meaning of the text. Psychological approaches include traditional psychoanalysis and depth-psychology, as well as historical psychology that uses insights and models from contemporary personality psychology and social psychology. Among social scientific approaches, memory studies look at the formation of textual traditions, including oral composition, transmission, and performance. Models of cultural memory also gained currency. Sociology, social history, and economic history shed light on the socioeconomic background of ancient religions. Religious studies had an intimate connection with anthropology especially in its early period, while models borrowed from cultural and structural anthropology influenced the study of Mediterranean values and social interactions more recently. Gender studies and feminist approaches initially focused on the reinterpretation of women’s roles in ancient religions and especially since the 1990s they addressed gender as a socially constructed category. Work on voluntary associations in the Greco-Roman world sheds light on the social context of private cults. Among new developments, postcolonial criticism both examines the colonial history of ancient cultures and addresses the colonial origins and inclinations of scholarship on religious antiquity. The approach of lived religion focusses on how individuals experience religion in their everyday lives. Cognitive science approaches study the evolutionary and psychological foundations of ancient religious thought and behavior, drawing especially on insights from neuroscience, experimental psychology, and evolutionary theory. Ritual studies employ models of individual and collective ritual behavior to understand cultic practices in religious antiquity. New approaches to magic move beyond cultural constructivism and use the concept as an analytical tool to understand a set of behaviors and attitudes. Insights from cognitive neuroscience have been applied to the study of religious experience. Cultural evolutionary theory has been employed to explain the success of particular religious movements and the development of oral and written traditions. Digital humanities include the computer-assisted collection and analysis of historical evidence and computer modeling tools, such as agent-based models. Finally, network science sheds new light on geographical, social, and textual patterns and dynamics in ancient religions.