Delaware City is a city in New Castle County, Delaware, United States. The population was 1,885 as of 2020. It is a small port town on the eastern terminus of the Chesapeake and Delaware Canal and is the location of the Forts Ferry Crossing to Fort Delaware on Pea Patch Island.

New Castle County is the northernmost of the three counties of the U.S. state of Delaware. As of the 2020 census, the population was 570,719, making it the most populous county in Delaware, with nearly 60% of the state's population of 989,948. The county seat is Wilmington, which is also the state's most populous city.