Ellsworth is a city in and the county seat of Hancock County, Maine, United States. The 2020 Census determined it had a population of 8,…Ellsworth is a city in and the county seat of Hancock County, Maine, United States. The 2020 Census determined it had a population of 8,399. Named after United States Founding Father Oliver Ellsworth, it contains historic buildings and other points of interest, and is close to Acadia National Park.