Battle of Hatchōoki

Battle of Hatchōoki
	Part of the Hokuetsu Campaign of the Boshin War
Date	August 10 – September 11, 1868
Location	Nagaoka, Echigo Province (now Niigata Prefecture)37°28′23.4″N 138°53′25.1″E / 37.473167°N 138.890306°E
Result	Nagaoka victory
Belligerents
Imperial forces Chōshū Domain;	Northern Alliance Nagaoka Domain; Aizu Domain; Kuwana Domain;
Commanders and leaders
Yamagata Aritomo	Kawai Tsugunosuke
Strength
	August: around 300 ; September: around 700
Casualties and losses
Unknown	131 dead
	Location within Japan

The Battle of Hatchōoki (八丁沖の戦い, Hatchōoki no tatakai) was an ambush in the middle of the Battle of Hokuetsu in the Boshin War by forces of Nagaoka Domain on forces loyal to the Imperial Court. The battle occurred in what is now the city of Nagaoka, in Niigata Prefecture.