Modesto is a village in Macoupin County, Illinois, United States. The population was 252 at the 2000 census.Modesto is located at 39°28′37″N 89°58′58″W / 39.47694°N 89.98278°W / 39.47694; -89.98278.According to the 2010 census, Modesto has a total area of 0.56 square miles, all land.As of the census of 2000, there were 252 people, 102 households, and 74 families residing in the village. The population density was 449.2 people per square mile. There were 109 housing units at an average density of 194.3 per square mile. The racial makeup of the village was 100.00% White.There were 102 households out of which 37.3% had children under the age of 18 living with them, 54.9% were married couples living together, 11.8% had a female householder with no husband present, and 26.5% were non-families. 25.5% of all households were made up of individuals and 18.6% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.91.