Rehoboth Beach is a city on the Atlantic Ocean along the Delaware Beaches in eastern Sussex County, Delaware, United States. As of 2020, its population was 1,108. Along with the neighboring coastal town of Lewes, Rehoboth Beach is one of the principal cities of Delaware's rapidly growing Cape Region. Rehoboth Beach lies within the Salisbury metropolitan area.

Sussex County is located in the southern part of the U.S. state of Delaware, on the Delmarva Peninsula. As of the 2020 census, the population was 237,378, making it the state's second most populated county only behind New Castle and ahead of Kent. The county seat is Georgetown.