Kuṇḍalinī (also kuṇḍalī, kuṭilā, kuṇḍalinī śakti), lit. “coiled,” is the grammatically female term that refers to a goddess and what is often understood as an energy usually located at the base of the human torso—and also found in the heart. She has a functional role in experiences of spiritual and bodily liberation or enlightenment where the awakening of kuṇḍalinī is a pivotal moment in the spiritual path. In early systems there are kuṇḍalinīs that move down as well as up (such as the Yoginīhṛdayadīpikā; see Tāntrikābhidānakośa [cited under Reference Works]). In some systems she is a blockage coiled at the base of the torso and her removal facilitates the entrance of breath into the central channel that delivers power and liberation (such as the 10th-century CE Pādmasaṃhitā 2.14 and the 13th-century Vasiṣṭhasaṃhitā 3.51). In other accounts, she herself rises upwards through the body, breaking impediments to liberation and delivering bodily or bodiless liberation (such as the Vāsiṣṭhasaṃhitā). Thus, kuṇḍalinī is experiential—but not merely on a cognitive or psychological level; in some formulations, she is a physiological or material aspect of the body. Emerging in the culturally specific context of Indian tantra she has taken on global significance and a myriad of interpretations. Diversely articulated from the earliest attestations, her continuing adaptation within disparate traditions demonstrates an enduring explanatory value and appeal. Kuṇḍalinī originates in sources on Indian tantra from the eighth century of the common era. Though most explicitly developed in Hindu tantra, she also emerges in Tibetan vajrayāna literature as cāṇḍālī. Kuṇḍalinī is adopted and developed in different Indian religious traditions, such as the Mokṣopāya, haṭha yoga, as well as Bengali tantric Vaiṣṇava and Orissan Siddha traditions. Esoteric snake imagery is also found transnationally in the premodern period though the scholarly treatments of kuṇḍalinī in material culture are few. In the modern period kuṇḍalinī influences, and is adapted within, locally inflected global esotericism, especially Theosophy. Kuṇḍalinī’s scientific and cultural reach is broad and deep as can be seen in her deployment by Carl Jung in the genesis of psychoanalysis. Kuṇḍalinī’s explanatory power for bodily and spiritual transformation, both mystic and empiricist, has been drawn on by popularizers in India, such as Vasant Rele and Gopi Krishna, and beyond the borders of the subcontinent. Kuṇḍalinī is the foundational rationale of contemporary yoga traditions, such as that popularized by Osho and Yogi Bhajan. Despite epistemological tensions, as a phenomenon bridging the experiential, spiritual, psychological, and bodily, kuṇḍalinī continues to be drawn on and to inspire psychological and scientific studies. Finally, kuṇḍalinī has been interpreted and reinterpreted in popular culture. Note that there is no section in this article on kuṇḍalinī in “classical” or Pātañjali Yoga, for kuṇḍalinī does not appear in that otherwise key 4th-century CE treatise on yoga. The focus in this article is given to academic sources despite the myriad popular sources on kuṇḍalinī that sometimes blur the line between scholar and practitioner. This is a particularly vexed problem in relation to kuṇḍalinī as there is a significant literature produced by a non-scholarly audience and this literature has had an important impact on the reception history and popularization of kuṇḍalinī. Non-scholarly works that I have excluded include Mary Scott’s Kundalini in the Physical World (1983), revised and published as The Kundalini Concept (2007), where kuṇḍalinī is presented through tantra and enmeshed with theosophy and psychology, and Kurt Leland’s Rainbow Body (2016), where kuṇḍalinī is part of the modern history of the cakra system examined therein.