Onida is a city in and the county seat of Sully County, South Dakota, United States. The population was 666 as of the 2020 census.
History
Onida was founded in 1880 by settlers from Oneida, New York. It received its city rights in 1883.
Geography
According to the United States Census Bureau, the city has a total area of , all land.
Climate
Demographics
2020 census
As of the 2020 census, Onida had a population of 666. The median age was 38.0 years. 25.5% of residents were under the age of 18 and 16.8% of residents were 65 years of age or older. For every 100 females there were 99.4 males, and for every 100 females age 18 and over there were 101.6 males age 18 and over.
0.0% of residents lived in urban areas, while 100.0% lived in rural areas.
There were 274 households in Onida, of which 29.9% had children under the age of 18 living in them. Of all households, 54.7% were married-couple households, 19.3% were households with a male householder and no spouse or partner present, and 17.2% were households with a female householder and no spouse or partner present. About 27.4% of all households were made up of individuals and 11.0% had someone living alone who was 65 years of age or older.
! Race !! Number !! Percent
|-
| White || 605 || 90.8%
|-
| Black or African American || 1 || 0.2%
|-
| American Indian and Alaska Native || 6 || 0.9%
|-
| Asian || 5 || 0.8%
|-
| Native Hawaiian and Other Pacific Islander || 0 || 0.0%
|-
| Some other race || 9 || 1.4%
|-
| Two or more races || 40 || 6.0%
|-
| Hispanic or Latino (of any race) || 22 || 3.3%
|}
2010 census
As of the census of 2010, there were 658 people, 280 households, and 186 families residing in the city. The population density was . There were 331 housing units at an average density of . The racial makeup of the city was 95.4% White, 1.8% Native American, and 2.7% from two or more races. Hispanic or Latino people of any race were 0.8% of the population.
There were 280 households, of which 33.9% had children under the age of 18 living with them, 57.1% were married couples living together, 6.1% had a female householder with no husband present, 3.2% had a male householder with no wife present, and 33.6% were non-families. 30.4% of all households were made up of individuals, and 9.6% had someone living alone who was 65 years of age or older. The average household size was 2.35 and the average family size was 2.91.
The median age in the city was 42.7 years. 25.8% of residents were under the age of 18; 4.1% were between the ages of 18 and 24; 23.2% were from 25 to 44; 29.9% were from 45 to 64; and 17% were 65 years of age or older. The gender makeup of the city was 53.5% male and 46.5% female.
2000 census
As of the census