As of the census of 2010, there were 1,124 people, 482 households, and 269 families residing in the city. The population density was. There were 615 housing units at an average density of. The racial makeup of the city was 91.3% White, 0.4% African American, 2.8% Native American, 0.1% Asian, 0.2% Pacific Islander, 2.2% from other races, and 3.0% from two or more races. Hispanic or Latino of any race were 5.2% of the population. There were 482 households of which 25.5% had children under the age of 18 living with them, 40.9% were married couplesliving together, 11.0% had a female householder with no husband present, 3.9% had a male householder with no wife present, and 44.2% were non-families. 40.5% of all households were made up of individuals and 19.1% had someone living alone who was 65 years of age or older. The average household size was 2.19 and the average family size was 2.86. The median age in the city was 48.1 years. 21.6% of residents were under the age of 18; 6.7% were between the ages of 18 and 24; 18.2% were from 25 to 44; 26.5% were from 45 to 64; and 26.8% were 65 years of age or older. The gender makeup of the city was 47.3% male and 52.7% female.
2000 census
As of the census of 2000, there were 1,342 people, 560 households, and 346 families residing in the city. The population density was 1,712.6 people per square mile. There were 652 housing units at an average density of 832.1 per square mile. The racial makeup of the city was 93.44% White, 0.52% African American, 3.35% Native American, 0.22% Asian, 0.15% Pacific Islander, 0.45% from other races, and 1.86% from two or more races. Hispanic or Latino of any race were 2.09% of the population. There were 560 households out of which 23.9% had children under the age of 18 living with them, 48.9% were married couples living together, 10.0% had a female householder with no husband present, and 38.2% were non-families. 35.2% of all households were made up of individuals and 18.4% had someone living alone who was 65 years of age or older. The average household size was 2.25 and the average family size was 2.90. In the city, the population was spread out with 23.0% under the age of 18, 7.9% from 18 to 24, 21.3% from 25 to 44, 19.8% from 45 to 64, and 27.9% who were 65 years of age or older. The median age was 43 years. For every 100 females, there were 83.8 males. For every 100 females age 18 and over, there were 80.6 males. The median income for a household in the city was $24,324, and the median income for a family was $32,574. Males had a median income of $21,490 versus $19,261 for females. The per capita income for the city was $14,153. About 6.8% of families and 11.1% of the population were below the poverty line, including 13.0% of those under age 18 and 9.5% of those age 65 or over.
Education
Sedan is a part of USD 286 Chautauqua County. Chautauqua County schools were consolidated in Sedan through school unification. Prior to school unification, the Sedan Blue Devils won the Kansas State High School class B baseball championship in 1973 and 2011.