Rosenhayn is an unincorporated community and census-designated place (CDP) located within Deerfield Township, in Cumberland County, in the U.S. state of New Jersey.

[9] According to the United States Census Bureau, the CDP had a total area of 2.654 square miles (6.87 km2), all land.

[10][11] The 2010 United States census counted 1,098 people, 382 households, and 274 families in the CDP.

Of all households, 23.0% were made up of individuals and 10.5% had someone living alone who was 65 years of age or older.

[8] As of the 2000 United States Census[4] there were 1,099 people, 373 households, and 286 families residing in the CDP.

17.7% of all households were made up of individuals, and 7.8% had someone living alone who was 65 years of age or older.