Riverside is a census-designated place (CDP) in Harford County, Maryland, United States. The population was 6,425 at the 2010 census. The term "Riverside" is generally used interchangeably with "Belcamp"; both names are accepted for the U.S. Postal Service's ZIP Code of 21017. However, the original community of Belcamp is located south of U.S. Route 40, outside the Riverside CDP.
Riverside is located at 39°28′35″N 76°14′42″W (39.476385, −76.244943). It is bordered to the north by Maryland Route 7 (Philadelphia Road) and to the south by U.S. Route 40 (Pulaski Highway). It extends west to the Bush River and James Run, and to the east it reaches to Grays Run. Maryland Route 543 (Riverside Parkway) passes through the center of the CDP, crossing Route 7 and ending at US 40. Just north of the CDP, MD 543 crosses Interstate 95 at Exit 80. I-95 leads southwest 30 miles (48 km) to Baltimore and northeast 45 miles (72 km) to Wilmington, Delaware. Bel Air, the Harford County seat, is 8 miles (13 km) northwest of Riverside via MD 543.