Valhalla is a hamlet and census-designated place (CDP) within the town of Mount Pleasant, in Westchester County, New York, United States, in the New York City metropolitan area. As of the 2020 census, Valhalla had a population of 3,213. The hamlet is known for being the home of the primary hospital campus of Westchester Medical Center and New York Medical College as well as the burial place of numerous notable people. Valhalla acquired its distinctive name not from the Kensico Cemetery directly, but through a decision by the local post office to avoid confusion with the existing "Kensico" train station and the newly established Kensico Cemetery. The name "Valhalla" was chosen by the wife of the postmaster, Andrew J. Kirch, who was an admirer of Richard Wagner's operas and, consequently, Norse mythology. In Norse lore, Valhalla is Odin's grand hall where the souls of valiant warriors are welcomed, a fitting, albeit coincidental, association for a community that would become home to a prominent cemetery. This renaming of the post office subsequently led to the hamlet itself adopting the name Valhalla around the early 20th century, with some sources indicating the train station's name also changed to Valhalla by 1904.