Racial and ethnic composition 2020 census As of the
2020 census, Round Lake Heights had a population of 2,622. The population density was , and the housing unit density was . The median age was 33.7 years. 28.2% of residents were under the age of 18 and 8.2% of residents were 65 years of age or older. For every 100 females there were 102.3 males, and for every 100 females age 18 and over there were 100.1 males age 18 and over. 100.0% of residents lived in urban areas, while 0.0% lived in rural areas. There were 783 households and 704 families in Round Lake Heights, of which 52.2% had children under the age of 18 living in them. Of all households, 60.0% were married-couple households, 16.6% were households with a male householder and no spouse or partner present, and 16.9% were households with a female householder and no spouse or partner present. About 12.8% of all households were made up of individuals and 3.4% had someone living alone who was 65 years of age or older. Of the village's housing units, 3.6% were vacant. The homeowner vacancy rate was 0.9% and the rental vacancy rate was 7.3%.
Income and poverty The median income for a household in the village was $74,286, and the median income for a family was $86,786. Males had a median income of $40,265 versus $30,515 for females. The
per capita income for the village was $24,854. About 9.7% of families and 8.4% of the population were below the
poverty line, including 11.3% of those under age 18 and 3.0% of those age 65 or over. ==Government==