As of the 2020 census, there were 8,472 people. The racial makeup of Millis is 92.3% White, 1.8% African American, 0.0% Native American, 1.7% Asian, 1.0% two or more races, and Hispanic or Latino of any race were 2.5% of the population. 11.1% of the population is foreign born and 14.9% of people over 5 years old speak a language other than English at home.
