Maryland Route 159 (MD 159) is a state highway in the U.S. state of Maryland. Known for most of its length as Perryman Road, the state highway runs 4.73 miles (7.61 km) from a dead end at the Bush River near Perryman north to U.S. Route 40 (US 40) and MD 7 in Aberdeen. The northernmost part of MD 159 was constructed in the early 1920s and became the original alignment of US 40. The Perryman Road portion of MD 159 was constructed in the late 1920s and early 1930s. MD 159 was extended west along what was MD 7 to US 40 in 1950.