First Bank, O'fallon Branch Basic Info Reviews Routing Numbers Map & Direction Name: First Bank, O'fallon Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 804 W Us Highway 50 O Fallon, Illinois 62269 St. Clair County View other branches Phone: 618-624-7162 Please enable JavaScript to view the comments powered by Disqus. Routing NumberProcess ACH TransferProcess Wire Transfer063114946YN081005794YN081009428YY081205109YN081205455YN121137506YN122239131YN From: To: