The Green Bank Observatory (previously National Radio Astronomy Observatory, Green Bank) is an astronomical observatory located in the National Radio Quiet Zone in Green Bank, West Virginia, U.S. It is the operator of the Robert C. Byrd Green Bank Telescope, the world's largest fully steerable radio telescope.
The observatory was established as the National Science Foundation's (NSF) National Radio Astronomy Observatory (NRAO) in 1956 and made its first observations in 1958. It served as the NRAO's headquarters until 1966, after which the facility was known as the National Radio Astronomy Observatory, Green Bank.
In October 2016, the observatory became an independent institution following a 2012 recommendation that the NSF fully divest itself from the facility by October 1, 2016.
Green Bank Observatory subsequently retained partial NSF funding, established private contracts, and formed a partnership with West Virginia University. It is operated by the nonprofit Associated Universities, Inc., under a cooperative agreement with the National Science Foundation.The observatory was involved in the search for signal from the MAVEN spacecraft in early 2026.