A jyotirliṅga (“liṅga of light”) is one of the foremost ways that the deity Śiva has been represented in mythology and art. It is an important sub-type of the deity’s liṅga (mark, sign, phallus). A well-known example is the network of twelve pilgrimage sites spread across the Indian subcontinent. In their related mythology each site accounts for a theophany of Śiva in light form, descending from heaven and remaining at the pilgrimage center in the form of a liṅga. The development and growth of this pilgrimage network within the sacred topographies of Śiva is relatively understudied, but new scholarship in the Purāṇas and Śaivadharma traditions as well as the archaeology of individual sites connected to these texts are helping to alleviate this paucity. Beginning in roughly the 10th century, fire and light imagery is integrated into different forms of Śaiva ritual, myth, and art as part of a strategy to popularize Śaivism. While the theme ‘God is light’ (numen lumen) is ubiquitous across religious traditions, its integration within Śaivism occurred for particular historical, theological, and sectarian reasons. One is the development of mythic themes related to light and fire as seen through the liṅgodbhavamūrti (form arising from the liṅga) and Devadāruvana (Pine Forest) mythemes. The earliest example of the liṅgodbhavamūrti likely dates to the 7th century, while the Devadāruvana can be traced to the Mahābhārata (Book 10.17). A second reason for the development of fire and light imagery is seen through the Śaiva encounter with Gupta period images of the Buddha’s fiery form and Buddhist commentarial literature. In addition, Śaiva encounters with universalizing tendencies within Islam, especially seen through the rise of Viśveśvara (Lord of the Universe) in Vārāṇasī, informed this developing tradition. Scholarship and sources about jyotirliṅgas can be structured around three major categories: the network of twelve jyotirliṅgas, the liṅgodbhavamūrti, and the Devadāruvana. Each of these categories has a diverse body of textual, inscriptional, art historical, and archaeological sources.