[5] The 2020 United States census counted 1,014 people, 374 households, and 319 families in Lake Quivira.

12.8% of households consisted of individuals and 8.0% had someone living alone who was 65 years of age or older.

[11] The percent of those with a bachelor's degree or higher was estimated to be 61.3% of the population.

There were 395 housing units at an average density of 280.1 per square mile (108.1/km2).

13.4% of all households were made up of individuals, and 7.9% had someone living alone who was 65 years of age or older.

There were 388 housing units at an average density of 297.8 per square mile (115.0/km2).

The racial makeup of the city was 97.10% White, 0.86% African American, 0.54% Asian, and 1.50% from two or more races.

26.3% were of English, 24.2% German, 9.7% Irish and 8.3% American ancestry according to Census 2000.

11.5% of all households were made up of individuals, and 6.6% had someone living alone who was 65 years of age or older.

About 0.9% of families and 1.3% of the population were below the poverty line, including none of those under the age of eighteen or sixty-five or over.