Mount Olive is a city in Macoupin County, Illinois, United States.

[3] The city is part of the Metro East region within the St. Louis metropolitan area.

Illinois Route 138 has its eastern terminus in the city, leading west 5 miles (8 km) to Benld.

Both routings are now local roads, as Interstate 55 now passes 1 mile (1.6 km) west of town, with access from Exit 44 (IL 138).

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.

In Mount Olive is located the Union Miners Cemetery where miners killed in the Battle of Virden and community and labor organizer Mary Harris "Mother" Jones are buried.