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.

Indian rock-cut architecture is more various and found in greater abundance in that country than any other form of rock-cut architecture around the world. Rock-cut architecture is the practice of creating a structure by carving it out of solid natural rock. Rock that is not part of the structure is removed until the only rock left makes up the architectural elements of the excavated interior. Indian rock-cut architecture is mostly religious in nature.