Kilbourne is a census-designated place in eastern Brown Township, Delaware County, Ohio, United States. As of the 2010 census it had a population of 139. The community has a post office with the ZIP code of 43032. It lies along State Route 521.Kilbourne was originally called Eden. A post office called Kilbourne has been in operation since 1837. The community has the name of James Kilbourne, surveyor.