The Lomas Rishi Cave, also called the Grotto of Lomas Rishi, is one of the man-made Barabar Caves in the Barabar and Nagarjuni hills of Jehanabad district in the Indian state of Bihar. This rock-cut cave was carved out as a sanctuary. It was built during the Ashokan period of the Maurya Empire in the 3rd century BC, as part of the sacred architecture of the Ajivikas, an ancient religious and philosophical group of India that competed with Jainism and became extinct over time. Ājīvikas were atheists and rejected ritualism of the Puranic karma Kāṇḍa as well as Buddhist ideas. They were ascetic communities and meditated in the Barabar caves. Still, the Lomas Rishi cave lacks an explicit epigraphical dedication to the Ajivikas, contrary to most other Barabar Caves, and may rather have been built by Ashoka for the Buddhists.

The Barabar Hill Caves are the oldest surviving rock-cut caves in India, dating from the Maurya Empire, some with Ashokan inscriptions, located in the Makhdumpur region of Jehanabad district, Bihar, India, 24 km (15 mi) north of Gaya.