FDIC-insured bank
Old Second National Bank — Aurora, IL
Bank headquartered in Aurora, Illinois, part of OLD SECOND BCORP INC.
Source: FDIC BankFind Suite, data as of June 30, 2026, fetched September 5, 2026
Headquarters and contact
| Address | 37 S River St Aurora, IL 60506 |
| County | Kane |
| Metro area | Chicago-Naperville-Elgin, IL-IN-WI |
| Website | www.oldsecond.com |
| Phone | not published in FDIC data, see the bank's website |
FDIC record
| FDIC Certificate | 3603 |
| Federal Reserve RSSD ID | 936136 |
| Status | Active |
| Charter class | N (OCC) |
| Holding company | OLD SECOND BCORP INC |
| Domestic offices | 57 |
| Financials as of | June 30, 2026 |
How to find your Old Second National Bank routing number
FDIC does not publish ABA routing numbers, and many banks use different routing numbers by state or by account type. The reliable places to find yours: the bottom left of a check from this bank, the "account details" screen in its online banking, or its official website at www.oldsecond.com.
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Offices nearest to headquarters
| Old Second National Bank main office Aurora, IL |
37 S River St, 60506 |
| Montgomery Branch Montgaomery, IL |
1830 Douglas Rd, 60538 |
| Farnsworth Branch Aurora, IL |
1350 N Farnsworth Ave, 60505 |
| North Aurora Branch North Aurora, IL |
200 John St, 60542 |
| West Galena Branch Aurora, IL |
2000 W Galena Blvd, 60506 |
| Oswego Branch Oswego, IL |
1200 Douglas Rd, 60543 |
| Orchard Branch Aurora, IL |
1230 N Orchard Rd, 60506 |
| Eola Road Branch Aurora, IL |
335 N Eola Rd, 60504 |
| Old Second Batavia Branch Batavia, IL |
1991 W Wilson St, 60510 |
| Sugar Grove Branch Sugar Grove, IL |
522 N Sugar Grove Pkwy, 60554 |
| Naperville Branch Naperville, IL |
2020 Feldott Ln, 60540 |
| Warrenville Branch Warrenville, IL |
Il-59, 60555 |
57 offices in total. Browse them by city through the state pages.
Where Old Second National Bank has offices
Cities with the most Old Second National Bank offices
Largest banks headquartered elsewhere in Illinois
| BMO Bank National Association Chicago | $254.97 billion |
| The Northern Trust Company Chicago | $178.57 billion |
| CIBC Bank USA Chicago | $66.50 billion |
| Busey Bank Champaign | $18.15 billion |
| Byline Bank Chicago | $9.91 billion |
| Wintrust Bank, National Association Chicago | $9.57 billion |
| Lake Forest Bank & Trust Company, National Association Lake Forest | $9.25 billion |
| First Mid Bank & Trust, National Association Mattoon | $9.14 billion |
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