Below is a list of Caseyville IL zip codes. For your research we have also included Caseyville Area Code, Time Zone, UTC and the local Saint Clair County FIPS Code. Each Caseyville Illinois zip code has a center Longitude / Latitude point (the Caseyville center is -90.033996582031 / 38.626499176025). For your convenience we have also indicated if that zip code in Caseyville observes Daylight Savings time.