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

There were 405 housing units at an average density of 274.4 per square mile (105.9/km2).

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.

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.