Blennerhassett is a census-designated place (CDP) in Wood County, West Virginia, United States. It is part of the Parkersburg-Marietta-Vienna, WV-OH Metropolitan Statistical Area. The population was 3,089 at the 2010 census.

Wood County is a county in the U.S. state of West Virginia. As of the 2020 census, the population was 84,296, making it West Virginia's fifth-most populous county. Its county seat is Parkersburg. The county was formed in 1798 from the western part of Harrison County and named for James Wood, governor of Virginia from 1796 to 1799.