| State: | AL |
| Type: | AL |
| Route: | 91 |
| Map Custom: | yes |
| Length Mi: | 38.161 |
| Length Ref: | [1] |
| Direction A: | South |
| Direction B: | North |
| Terminus A: | in Wilburn |
| Junction: | near Hanceville in Hanceville |
| Terminus B: | in Holly Pond |
| Previous Type: | US |
| Previous Route: | 90 |
| Next Type: | AL |
| Next Route: | 92 |
State Route 91 (SR 91) is a 38.161adj=midNaNadj=mid state highway located entirely within Cullman County in the northern part of the U.S. state of Alabama. The southern terminus of the highway is at an intersection with SR 69 in Wilburn, a small unincorporated community in the southwestern part of the county that is also known as Bug Tussle. The northern terminus of the highway is at an intersection with U.S. Route 278 (US 278) in Holly Pond.
SR 91 is a two-lane highway that travels through rural areas of Cullman County. Although it is signed as a north–south highway, the first 8miles of the highway from its southern terminus actually travels in southeasterly direction. In Arkadelphia, the highway takes a virtual 90-degree turn to the left and assumes a northeasterly trajectory, which it maintains for the duration of its length.
SR 91 has an interchange with Interstate 65 (I-65) approximately 11miles southwest of Hanceville, and provides a connecting route for motorists heading to and from this town. Our Lady of the Angels Monastery, founded by Mother Angelica, is located near SR 91 between I-65 and Hanceville.
Much of the highway between Wilburn and I-65 is a narrow winding road through hilly rural terrain. In some places, the road is actually substandard for it to be a numbered state route. However, from I-65 north and east, the roadway is substantially better and contains less sharp turns and short sightlines.