Seaford is a city located along the Nanticoke River in Sussex County, Delaware. According to the 2007 Census Bureau figures, the population of the city is 7,185 . It the principal city of the Seaford Micropolitan Statistical Area, which includes all of Sussex County. It is the largest city in Sussex county and was voted the 28th Best Small Town in America.. It hosted the Seaford Eagles of the Eastern Shore Baseball League.