Maryland Route 281 (MD 281) is a state highway in the U.S. state of Maryland. Known for most of its length as Red Hill Road, the state highway runs 2.12 miles (3.41 km) from MD 7 east to the Delaware state line within Elkton. MD 281 and its continuation in Delaware were originally blazed in the 18th century as part of the Old Post Road between Baltimore and Philadelphia. The state highway was part of the Elk and Christiana Turnpike in the early 19th century and later the Old Baltimore Pike, but was replaced as the main highway east from Elkton by U.S. Route 40 (US 40) in the early 20th century. The modern MD 281 was mostly constructed and marked around 1960.

MD 281 begins at an intersection with MD 7 in the town of Elkton. MD 7 continues west as Main Street and heads southeast as Delaware Avenue toward US 40. MD 281 heads east as two-lane Main Street. After crossing Big Elk Creek and leaving the town limits, the name of the state highway changes to Red Hill Road. MD 281 crosses the northern flank of Grays Hill before meeting the northern end of MD 781 (Delancy Road). After crossing under transmission lines, MD 281 reaches its eastern terminus at the Delaware state line. The highway continues straight as Old Baltimore Pike toward Christiana.

What is now MD 281 and its continuation in Delaware was the Old Post Road used to connect Christiana Bridge with the head of the Elk River, and by extension Philadelphia and Baltimore, in the 18th century. Alternatively known as Old Baltimore Pike, this road was used by the French army during their march from Newport, Rhode Island to Yorktown during the Revolutionary War, passing through the area in September 1781. In 1817, the Elk and Christiana Turnpike was completed along the path of the Old Post Road; the turnpike operated until 1838, when Old Baltimore Pike reverted to a public road. By the 1920s, the Old Baltimore Pike was supplanted by a parallel highway to the south from Elkton to Wilmington that was chosen as the route of US 40. The first segment of the modern MD 281 was a stub of state maintenance from MD 7 (then US 40) east a few blocks toward Big Elk Creek constructed around 1933. This stub remained until MD 281 was completed to the Delaware state line in 1959 and 1960, when the modern bridge over Big Elk Creek was completed.

The entire route is in Elkton, Cecil County.