Rosaryville is an unincorporated area and census-designated place (CDP) in Prince George's County, Maryland, United States, located south of Clinton and Upper Marlboro beside U.S. Route 301.

[4] Close to Rosaryville are the Marlton housing development, Maryland Veterans Cemetery, the Southern Maryland Farmers Market, and Rosaryville State Park.

[5] George Washington Parke Custis was born in Rosaryville, Maryland on April 30, 1781.

There were 4,267 housing units at an average density of 312.2 per square mile (120.5/km2).

14.3% of all households were made up of individuals, and 3.6% had someone living alone who was 65 years of age or older.

Prince George's County Police Department District 5 Station in Clinton CDP serves the community.