The Sree Kallely Oorali Appooppan Kavu is an ancient temple nestled along the banks of the Achankovil River in Kalleli, located in the Pathanamthitta district of Kerala, India. It is positioned on the Kalleli–Achankovil forest route, approximately 19 km (12 mi) from the district headquarters in Pathanamthitta.
The presiding deity of the Oorali Appooppan Kavu is Oorali Appooppan, revered as the lord of the mountain gods. The temple's main festival, celebrated with great fervor, is Pathamudayam.
The temple adheres to the customs and rituals of the early Dravida-Naga tribes, distinguishing itself from the conventional tantric practices and ceremonies observed in typical Hindu temples.
The primary deities of the temple are Oorali Appooppan, also known as Kalleli Appooppan, and Oorali Ammoomma. Appooppan is revered as the lord of the 999 Mala Daivangal.