Worthington is a home rule-class city on the south bank of the Ohio River in Greenup County, Kentucky, in the United States. The population w…Worthington is a home rule-class city on the south bank of the Ohio River in Greenup County, Kentucky, in the United States. The population was 1,609 as of the 2010 U.S. census. Worthington is a part of the Huntington-Ashland-Ironton metropolitan area. As of the 2010 census, the MSA had a population of 287,702.