2020 census As of the
2020 census, Seymour had a population of 2,575. The median age was 44.2 years; 24.0% of residents were under the age of 18 and 24.2% of residents were 65 years of age or older. For every 100 females there were 90.2 males, and for every 100 females age 18 and over there were 84.9 males age 18 and over. 0.0% of residents lived in urban areas, while 100.0% lived in rural areas. There were 1,129 households and 839 families residing in the city. Of all households, 28.2% had children under the age of 18 living in them, 39.7% were married-couple households, 20.6% were households with a male householder with no spouse or partner present, and 33.2% were households with a female householder with no spouse or partner present. About 37.3% of all households were made up of individuals and 19.3% had someone living alone who was 65 years of age or older. There were 1,359 housing units, of which 16.9% were vacant. The homeowner vacancy rate was 2.5% and the rental vacancy rate was 9.6%.
2010 census As of the census of 2010, 2,740 people, a decrease of 5.78% since 2000 (168 people). The
racial makeup of the town was 91.28% White, 2.45% African American, 0.22% Native American, 0.11% Asian, 0.11% Pacific Islander, 4.11% from other races, and 3.80% from two or more races. Hispanics or Latinos of any race were about 3.6% of the population. Of 1,451 housing units, 249 were vacant.
2000 census As of the census of 2000, 2,908 people, 1,273 households, and 790 families resided in the city. The population density was 1,067.5 people/sq mi (412.8/km). The 1,534 housing units averaged 563.1/sq mi (217.8/km). The
racial makeup of the city was 89.24% White, 4.57% African American, 0.48% Native American, 0.72% Asian, 3.54% from other races, and 1.44% from two or more races. About 10.45% were Hispanic or Latino of any race. Of the 1,273 households, 26.0% had children under the age of 18 living with them, 49.1% were married couples living together, 10.0% had a female householder with no husband present, and 37.9% were not families; 35.7% of all households were made up of individuals, and 21.9% 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 age distribution was 24.3% under 18, 6.1% from 18 to 24, 20.9% from 25 to 44, 23.9% from 45 to 64, and 24.8% who were 65 or older. The median age was 44 years. For every 100 females, there were 83.2 males. For every 100 females age 18 and over, there were 79.6 males. The median income for a household in the city was $23,662, and for a family was $32,917. Males had a median income of $21,891 versus $19,292 for females. The per capita income for the city was $16,062. About 15.6% of families and 19.5% of the population were below the poverty line, including 31.8% of those under age 18 and 10.7% of those age 65 or over. ==Education==