| Building Name: | Udayagiri Raja Maha Vihara |
| Native Name: | උදයගිරි රජ මහා විහාරය |
| Location: | Udayagiri, Ampara, Sri Lanka |
| Coordinates: | 7.3824°N 81.6326°W |
| Province: | Eastern Province, Sri Lanka |
| District: | Ampara |
| Heritage Designation: | Archaeological protected monument (26 December 2014) |
| Architecture: | yes |
| Architecture Type: | Buddhist Temple |
Udayagiri Raja Maha Vihara (Sinhalaː උදයගිරි රජ මහා විහාරය) is an ancient Buddhist Temple situated in Ampara District, Sri Lanka. The temple has been built in the village called Udayagiri, and located about 1km (01miles) distance to Ampara – Mahaoya Road. The temple has been formally recognised by the Government as an archaeological site in Sri Lanka.
It is believed that the history of this temple goes back over 1000 years. But according to the features of archaeological remains in the Vihara premises, archaeologists assume that this temple may have been established during the pre–Christian era.[1] A stone pillar with an inscription at the entrance of Vihara states that this Vihara was exempted from taxes by two generals of King Udaya I (901 - 912).