Mason is an incorporated town in Effingham County, Illinois, United States.

[4] It was named after Roswell Mason, an official of the Illinois Central Railroad.

[5] Mason is part of the Effingham, IL Micropolitan Statistical Area.

Interstate 57 crosses the northwest corner of Mason, but the closest access is from Edgewood to the southwest or from Exit 151 4 miles (6 km) to the northeast.

23.36% of all households were made up of individuals, and 12.15% had someone living alone who was 65 years of age or older.