Herrin is a city in Williamson County, Illinois, United States. The population was 12,501 at the 2010 census.
The city is part of the Marion-Herrin Micropolitan Area and is a part of the Carbondale-Marion-Herrin, Illinois Combined Statistical Area with 123,272 residents, the sixth most populous Combined statistical area in Illinois.
Herrin is located at 37°48′9″N 89°1′41″W (37.802412, -89.028093).
According to the 2010 census, Herrin has a total area of 9.461 square miles (24.50 km2), of which 9.23 square miles (23.91 km2) (or 97.56%) is land and 0.231 square miles (0.60 km2) (or 2.44%) is water.
The settlement of Herrin started out as scattered settlers on Herring's Prairie named for the first permanent settler Isaac Herring, a Baptist preacher. Later, his son-in-law David Herrin arrived and the similarity in names led to the eventual shortening of the name to just Herrin's Prairie. The trails from Jordan's fort to Humphreys' ford on the Big Muddy River intersected the old trail from Lusk's ferry at modern-day Golconda to Kaskaskia, which was first settled by French colonists.
Isaac Herring entered the first land in what became Herrin on 4 November 1816, two years before Illinois became a state. He paid $2 an acre for the 160 acres (65 ha). At the time he lived to the west in Jackson County, the land entry was the northeast quarter off Section 30, Township 8 South, Range 2 East of the Third Principal Meridian. Today that area runs between 17th and 27th streets, and from West Cherry Street on the north to West Stotlar Street on the south.
David Ruffin Harrison started storekeeping on the prairie in 1858. During the Civil War, he built a frame store building and secured a fourth class post office that opened on 26 May 1864.