Maryland Route 91 (MD 91) is a state highway in the U.S. state of Maryland. the state highway runs 7.86 miles (12.65 km) from MD 32 at Gamber north to MD 30 near Upperco. MD 91 connects southeastern Carroll County and the far western part of Baltimore County south of Hampstead with MD 140 at Finksburg. The state highway was paved at Finksburg in the early 1910s. The remainder of MD 91 was constructed in the mid- to late 1920s.