Hyattsville is a city in Prince George's County, Maryland, United States. It is an urban suburb of Washington, D.C. The population was 21,187 at the 2020 United States census. Before Europeans reached the area, the upper Anacostia River was home to Nacotchtank/Anaquashtank people, a Piscataway-speaking Algonquian peoples who lived throughout what is now the Washington, D.C., area. European encroachment and diseases decimated their population and by the 1680s the Nacotchtank/Anaquashtank had largely moved away and merged with other tribes.