Teradomari (寺泊町 Teradomari-machi?) was a town located in Santō District, Niigata Prefecture, Japan.
As of 2003, the town had an estimated population of 11,766 and a density of 202.30 persons per km². The total area was 58.16 km².
On January 1, 2006, Teradomari, along with the city of , the town of Yoita, and the village of Washima (all from Santō District), was merged into the expanded city of Nagaoka.