Etna, IllinoisEtna is an unincorporated community in Coles County, Illinois, United States. It lies at an elevation of 656 feet.The community is part of the Charleston-Mattoon Micropolitan Statistical Area.HistoryA variant name was "Aetna". A post office called Etna was established in 1859, and remained in operation until 1943. The community was named after Mount Etna, on Sicily.