Maryland's 8th congressional district is concentrated almost entirely in Montgomery County, with a small portion in Prince George's County. Adjacent to Washington, D.C., the 8th district takes in many of the city’s wealthiest inner-ring suburbs, including Bethesda, Chevy Chase, and Potomac. It also includes several more economically and racially diverse communities, the most populous of which are Rockville and Silver Spring.

Prince George's County is located in the U.S. state of Maryland bordering the eastern portion of Washington, D.C. As of the 2020 U.S. census, the population was 967,201, making it the second-most populous county in Maryland, behind neighboring Montgomery County. The 2020 census counted an increase of nearly 104,000 in the previous ten years. Its county seat is Upper Marlboro. It is the largest and the second most affluent African American-majority county in the United States, with five of its communities identified in a 2015 top ten list.