2020 census As of the
2020 census, Selby had a population of 610. The median age was 51.9 years. 18.7% of residents were under the age of 18 and 31.6% of residents were 65 years of age or older. For every 100 females there were 97.4 males, and for every 100 females age 18 and over there were 94.5 males age 18 and over. 0.0% of residents lived in urban areas, while 100.0% lived in rural areas. There were 257 households in Selby, of which 23.7% had children under the age of 18 living in them. Of all households, 45.1% were married-couple households, 20.6% were households with a male householder and no spouse or partner present, and 27.6% were households with a female householder and no spouse or partner present. About 40.9% of all households were made up of individuals and 27.2% had someone living alone who was 65 years of age or older. Of the 300 households 19.0% had children under the age of 18 living with them, 51.3% were married couples living together, 4.7% had a female householder with no husband present, 2.3% had a male householder with no wife present, and 41.7% were non-families. 39.0% of households were one person and 22.6% were one person aged 65 or older. The average household size was 1.98 and the average family size was 2.62. The median age was 52.9 years. 16% of residents were under the age of 18; 3.4% were between the ages of 18 and 24; 18.7% were from 25 to 44; 27.8% were from 45 to 64; and 34.1% were 65 or older. The gender makeup of the city was 51.2% male and 48.8% female.
2000 census At the
2000 census, there were 736 people in 308 households, including 199 families, in the city. The population density was . There were 335 housing units at an average density of . The
racial makup of the city was 98.10% White, 1.36% Native American, 0.14% from other races, and 0.41% from two or more races. Hispanic or Latino of any race were 0.27% of the population. Of the 308 households 23.4% had children under the age of 18 living with them, 57.1% were married couples living together, 5.8% had a female householder with no husband present, and 35.1% were non-families. 34.1% of households were one person and 21.4% were one person aged 65 or older. The average household size was 2.16 and the average family size was 2.74. The age distribution was 20.4% under the age of 18, 3.4% from 18 to 24, 20.5% from 25 to 44, 25.3% from 45 to 64, and 30.4% 65 or older. The median age was 51 years. For every 100 females, there were 92.7 males. For every 100 females age 18 and over, there were 86.6 males. The median household income was $27,639 and the median family income was $37,500. Males had a median income of $26,563 versus $18,214 for females. The per capita income for the city was $16,433. About 4.7% of families and 8.3% of the population were below the
poverty line, including 2.6% of those under age 18 and 16.1% of those age 65 or over. ==Notable people==