Every FDIC-insured bank branch in St. Clair County, Illinois as of June 30, 2025. County land area: 658 square miles, 10.2 branches per 100 sq mi.
| Institution | Branches | Deposits |
|---|---|---|
| Regions Bank | 12 | $848.3M |
| First National Bank of Waterloo | 8 | $276.6M |
| FCB Banks | 4 | $367.8M |
| Citizens Community Bank | 4 | $417.7M |
| U.S. Bank National Association | 4 | $205.7M |
| First Bank | 3 | $189.1M |
| Busey Bank | 3 | $436.9M |
| The Farmers and Merchants National Bank of Nashville | 3 | $25.9M |
| Associated Bank, National Association | 3 | $468.9M |
| The Central Trust Bank | 2 | $116.4M |
| Bank of O'Fallon | 2 | $319.7M |
| Bank of Springfield | 2 | $109.6M |
| Commerce Bank | 2 | $246.8M |
| First FSB of Mascoutah | 2 | $153.2M |
| Bank of America, National Association | 2 | $422.0M |
| Midland States Bank | 1 | $48.8M |
| Lindell Bank & Trust Company | 1 | $32.3M |
| Carrollton Bank | 1 | $447.5M |
| BMO Bank National Association | 1 | $57.3M |
| Heartland Bank and Trust Company | 1 | $61.5M |
| Woodforest National Bank | 1 | $4.2M |
| First Mid Bank & Trust, National Association | 1 | $63.0M |
| Bank of Belleville | 1 | $352.3M |
| JPMorgan Chase Bank, National Association | 1 | $34.1M |
| PNC Bank, National Association | 1 | $63.6M |
| UMB Bank, National Association | 1 | $55.4M |