was a town located in Santà  District, Niigata Prefecture, Japan.
As of 2003, the town had an estimated population of 11,766 and a density of 202.30 persons per km<sup>2</sup>. The total area was 58.16 km<sup>2</sup>.
On January 1, 2006, Teradomari, along with the city of Tochio, the town of Yoita, and the village of Washima (all from Santà  District), was merged into the expanded city of Nagaoka.
In addition to this line, Echigo Kotsu Nagaoka Line() had been operated in the town until 1975.