Coldwater is a city in and the county seat of Comanche County, Kansas, United States. As of the 2010 census, the city population was 828.
Coldwater is located at 37°16′10″N 99°19′34″W / 37.26944°N 99.32611°W / 37.26944; -99.32611 (37.269553, -99.326061). According to the United States Census Bureau, the city has a total area of 3.0 square miles (7.7 km²), of which, 2.6 square miles (6.8 km²) of it is land and 0.3 square miles (0.9 km²) of it (11.45%) is water.
As of the census of 2000, there were 792 people, 380 households, and 209 families residing in the city. The population density was 301.3 people per square mile (116.3/km²). There were 460 housing units at an average density of 175.0 per square mile (67.5/km²). The racial makeup of the city was 98.11% White, 0.13% African American, 0.63% Native American, 0.13% Pacific Islander, 0.13% from other races, and 0.88% from two or more races. Hispanic or Latino of any race were 2.15% of the population.