The Romaka Siddhanta (Sanskrit: रोमकसिद्धान्त, romanized: Romaka Siddhānta), literally "The Doctrine of the Romans", is one of the five siddhantas (doctrine or tradition) mentioned in Varahamihira's Panchasiddhantika which is an Indian astronomical treatise.
Romaka Siddhanta is based on the astronomical learning of the Byzantine Empire, also referred to as the Eastern Roman Empire.[1][2]