North Dakota Highway 91 (ND 91) is a 0.523-mile-long (0.842 km) east–west state highway in the U.S. state of North Dakota.

ND 91's western terminus is at U.S. Route 52 (US 52) in Harvey, and the eastern terminus is at ND 3 in Harvey.

[1] The entire route is in Harvey, Wells County.