The following highways are numbered 391:
Canada Manitoba Provincial Road 391 Newfoundland and Labrador Route 391 Quebec Route 391
Japan Japan National Route 391
United States Interstate 391 Colorado State Highway 391 Florida State Road 391 New York State Route 391 Puerto Rico Highway 391 South Carolina Highway 391 South Dakota Highway 391 Tennessee State Route 391 Virginia State Route 391 Wyoming Highway 391