[4] The 2020 United States census counted 17 people, 9 households, and 5 families in Ionia.

There were 19 housing units at an average density of 19.5 per square mile (7.5/km2).

33.3% of households consisted of individuals and 11.1% had someone living alone who was 65 years of age or older.

[6][10] The percent of those with a bachelor’s degree or higher was estimated to be 0.0% of the population.

[6] The community is served by Rock Hills USD 107 public school district.