U.S. Route 50 (US 50) is a major east–west route of the U.S. Highway System, stretching just over 3,000 miles (4,800 km) from Ocean City, Maryland, on the Atlantic Ocean, to West Sacramento, California, nearly to the Pacific Ocean. In Washington, D.C., US 50 passes between Arlington County, Virginia, and Prince George's County, Maryland, predominantly along surface streets, including a part of Constitution Avenue along the National Mall.

U.S. Route 50 is a transcontinental highway which stretches from Ocean City, Maryland to West Sacramento, California. In the U.S. state of Virginia, US 50 extends 86 miles (138 km) from the border with Washington, D.C. at a Potomac River crossing at Rosslyn in Arlington County to the West Virginia state line near Gore in Frederick County.