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Post Offices in St. Clair County, IL
28 post offices · Data as of 09/23/2026
Post offices on this page
Post offices in St. Clair County at a glance
- St. Clair County has 28 post offices, about 1.1 for every 10,000 residents.
- That is about the same as the Illinois average (1.1 per 10,000).
- It ranks 6th among 102 Illinois counties by number of post offices.
- Close by, St. Louis County, MO (41), Madison County (33) and St. Louis city, MO (16) have post offices as well.
Post offices in St. Clair County
A to Z
- Alorton Post OfficeZIP 622074825 Bond Ave, East St Louis, IL
- Belleville Post OfficeZIP 62220120 W Washington St, Belleville, IL
- Belleville Post OfficeZIP 622235731 Mt Pleasant Ln, Belleville, IL
- Caseyville Post OfficeZIP 62232113 S Long St, Caseyville, IL
- Dupo Post OfficeZIP 62239116 Emma Ave, Dupo, IL
- East Carondelet Post OfficeZIP 62240824 State St, East Carondelet, IL
- East Saint Louis Post OfficeZIP 622074825 Bond Ave, East Saint Louis, IL
- East Saint Louis Post OfficeZIP 622013900 Collinsville Rd, East Saint Louis, IL
- East Saint Louis Post OfficeZIP 62206801 Range Ln, East Saint Louis, IL
- East St Louis Post OfficeZIP 622038701 State St, East St Louis, IL
- East St Louis Post OfficeZIP 62201950 Missouri Ave, East St Louis, IL
- Fairview Heights Post OfficeZIP 6220810850 Lincoln Trl, Unit 20, Fairview Heights, IL
- Freeburg Post OfficeZIP 622433 S Belleville St, Freeburg, IL
- Lebanon Post OfficeZIP 62254201 Federal Aid Secondary 1780, Lebanon, IL
- Lenzburg Post OfficeZIP 62255312 N Charles St, Lenzburg, IL
- Lovejoy Post OfficeZIP 62059413 S 3rd St, Lovejoy, IL
- Marissa Post OfficeZIP 62257114 N Main St, Marissa, IL
- Mascoutah Post OfficeZIP 6225818 W Main St, Mascoutah, IL
- Mascoutah Post OfficeZIP 6225818 W Main St, Mascoutah, IL
- Millstadt Post OfficeZIP 6226020 W White St, Millstadt, IL
- New Athens Post OfficeZIP 62264200 S Benton St, New Athens, IL
- O'Fallon Post OfficeZIP 622691111 S Lincoln Ave, O'Fallon, IL
- Saint Libory Post OfficeZIP 622827340 State Route 15, Saint Libory, IL
- Scott AFB Post OfficeZIP 62225404 W Martin St, Scott AFB, IL
- Scott Air Force Base Post OfficeZIP 62225404 W Martin St, Scott Air Force Base, IL
- Smithton Post OfficeZIP 62285512 S Main St, Smithton, IL
- Smithton Post OfficeZIP 62285512 S Main St, Smithton, IL
- Summerfield Post OfficeZIP 62289101 E Park St, Summerfield, IL
Frequently asked questions
- How many post offices are in St. Clair County, IL?
- There are 28 post offices in St. Clair County as of 09/23/2026.