First County Bank, O'fallon Branch Basic Info Reviews Routing Numbers Map & Direction Name: First County Bank, O'fallon Branch Main Office: No Service: Full Service Brick and Mortar Office Location: 1501 West Highway 50 O Fallon, Illinois 62269 St. Clair County View other branches Phone: 618-622-9090 Please enable JavaScript to view the comments powered by Disqus. From: To: