Kesen (気仙郡, Kesen-gun) is a rural district in Iwate Prefecture, in the Tōhoku region of northern Japan.
[1] Formerly, the area of the cities of Rikusentakata and Ōfunato were within the borders of the district.
As of 1 June 2019[update] the district consists only of the town of Sumita with a population of 5,228 people, with a density of 15.6 per km2 and an area of 334.84 square kilometres (129.28 sq mi).
During the Edo period under the Tokugawa shogunate, the district was within Mutsu Province and was under the control of the Date clan of the Sendai Domain.
On April 1, 1889, with the establishment of the municipalities system, the district was organized into two towns (Sakari and Takata) and 20 villages.