The Upapuranas are a collection of secondary Hindu Puranic texts that preserve mythology, religious teachings, rituals, sacred traditions, genealogies, and stories of gods, sages, kings, and devotees. Unlike the eighteen Mahapuranas, the Upapuranas generally focus on more specific deities, regional traditions, religious practices, and theological subjects, reflecting the diversity of Hindu religious literature.

The term "Upapurana" means "secondary Purana." Although traditionally considered distinct from the eighteen Mahapuranas, the Upapuranas form an important part of the broader Puranic tradition. Different traditions recognize different groups of Upapuranas, and their contents and classifications vary considerably across historical sources.

Many of the original Upapurana texts have been lost, survive only in fragments, or are preserved in incomplete and varying manuscripts. As a result, reconstructing their contents and histories can be difficult. One of the most important modern sources for studying these texts is Studies in the Upapuranas by R.C Hazra, which examines the surviving material and traditions surrounding the Upapuranas.