Mount Olive is a city in Macoupin County, Illinois, United States. The population was 2,015 at the 2020 census. The city is part of the Metro East region within the St. Louis metropolitan area. Geography Mount Olive is located in southeastern Macoupin County at (39.071624, -89.726719). Illinois Route 138 has its eastern terminus in the city, leading west to Benld. Former U.S. Route 66 passed through the north and west sides of the city and later on a wider alignment farther north and west of the city. Both routings are now local roads, as Interstate 55 now passes west of town, with access from Exit 44 (IL 138). Old Route 66 leads northeast to Litchfield and southwest to Staunton, and I-55 leads north to Springfield and southwest to St. Louis. According to the U.S. Census Bureau, Mount Olive has a total area of , of which , or 0.26%, are water. The city drains west to tributaries of Cahokia Creek, a west-flowing direct tributary of the Mississippi River, and southeast to Silver Creek, a south-flowing tributary of the Kaskaskia River. Demographics As of the census of 2000, there were 2,150 people, 906 households, and 609 families residing in the city. The population density was . There were 991 housing units at an average density of . The racial makeup of the city was 96.79% White, 0.83% Native American, 0.64% Asian, 1.28% from other races, and 0.47% from two or more races. Hispanic or Latino of any race were 3% of the population. There were 906 households, out of which 30.7% had children under the age of 18 living with them, 54.6% were married couples living together, 8.9% had a female householder with no husband present, and 32.7% were non-families. 29.6% of all households were made up of individuals, and 19.3% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 2.92. In the city, the population was spread out, with 23.5% under the age of 18, 7.7% from 18 to 24, 28.8% from 25 to 44, 19.9% from 45 to 64, and 20.1% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 95.6 males. For every 100 females age 18 and over, there were 88.6 males. The median income for a household in the city