U.S. Route 13 Business is a business route of US 13 in the U.S. state of Maryland. The highway runs 8.14 miles (13.10 km) between US 13 south of Fruitland and US 13 and US 50 on the north side of Salisbury. US 13 Bus. is a four-lane highway with divided and undivided sections that provides access to Salisbury University, downtown Salisbury, where the highway intersects US 50 Bus., and Fruitland, where the highway meets Maryland Route 513 (MD 513). US 13 Bus. was constructed as a new alignment of US 13 in several steps in the 1930s and early 1940s. The section of the highway through Salisbury was originally constructed with four lanes, while the portion of the highway through Fruitland and at the northern end was expanded to a divided highway in the first half of the 1950s. US 13 Bus. was designated when US 13 was moved to the Salisbury Bypass upon its completion in 1981.

U.S. Route 13 (US 13) is a United States Numbered Highway running from Fayetteville, North Carolina, north to Morrisville, Pennsylvania. In the U.S. state of Maryland, the route runs 42.48 miles (68.36 km) from the Virginia border south of Pocomoke City in Worcester County north to the Delaware border in Delmar, Wicomico County, where the route intersects Maryland Route 54 (MD 54)/Delaware Route 54 (DE 54), which runs along the state line. The majority of the route within Maryland is a four-lane divided highway that passes through rural areas of woodland and farmland. The route also runs through a few municipalities including Pocomoke City and Princess Anne and it bypasses Fruitland and Salisbury to the east on the Salisbury Bypass, which is a freeway. US 13 intersects many major roads including the southern terminus of US 113 in Pocomoke City, MD 413 in Westover, and MD 12 and US 50 where the route is on the Salisbury Bypass. The route shares a concurrency with US 50 along a portion of the Salisbury Bypass.