Upayāja (Upayaja) is a sage. Maharṣi (Maharshi; Great Sage) Yāja (Yaja) and Upayāja were two brothers. When Drupada, king of Pāñcāla (Panchala), performed a yajña (yajna) in order to get a son to kill Drupada, they became the priest of that yajña.
[See Yāja ]