United States Government--post Office Oldenburg, IN 47036 Phone : (812) 934-4819 Business Category Post Offices Government Offices & Public Schools Post Office - Oldenburg 22133 Main St Oldenburg, IN 47036 Phone : (812) 934-4819 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (812) 933-1512