Foodservice distributor Dot Foods is based in Mount Sterling.

During the 1987 competition, the town of Flora famously produced the "Is We Is or Is We Isn't/Gonna Get Ourselves A Prison" video.

Ultimately, Mount Sterling won the 1987 competition and the state constructed the Western Illinois Correctional Center along State Highway 99 a mile south of town.

According to the 2021 census gazetteer files, Mount Sterling has a total area of 1.11 square miles (2.87 km2), all land.

42.26% of all households were made up of individuals, and 14.12% had someone living alone who was 65 years of age or older.