U.S. Route 50 or U.S. Highway 50 is a major east–west route of the U.S. Highway system, stretching just over 3,000 miles from Interstate 80 in West Sacramento, California, to Maryland Route 528 in Ocean City, Maryland, on the Atlantic Ocean. Until 1972, when it was replaced by Interstate Highways west of the Sacramento area, it extended to San Francisco, near the Pacific Ocean. The Interstates were constructed later and are mostly separate from this route. It generally serves a corridor south of I-70 and I-80 and north of I-64 and I-40.
The route runs through mostly rural desert and mountains in the western United States, with the section through Nevada known as "The Loneliest Road in America". In the Midwest, US 50 heads through mostly rural areas of farms as well as a few large cities including Kansas City, Missouri; St. Louis, Missouri; and Cincinnati, Ohio.
The route continues into the eastern United States, where it passes through the Appalachian Mountains in West Virginia before heading through Washington, D.C. From there, US 50 continues through Maryland as a high-speed road to Ocean City.