Ellendale is a town in Sussex County, Delaware, United States. The population was 487 at the 2020 census, an increase of 27.8% since the 2010 census, and a 48.9% increase since the year 2000. It is part of the Salisbury, Maryland-Delaware Metropolitan Statistical Area. Ellendale is the "Gateway to Delaware's Resort Beaches" because it is the town located on U.S. Route 113, the resort area's westernmost border, and Delaware Route 16, the resort area's northernmost border with the eastern border being the Delaware Bay and Atlantic Ocean and the southern border being the state line with Maryland.