The following highways are numbered 181:
Canada Prince Edward Island Route 181
Chile Route 181-CH in Araucanía Region
Cuba
Guanabacoa–Cotorro Road (2–181)
India National Highway 181 (India)
Ireland R181 road (Ireland)
Japan Japan National Route 181
United Kingdom M181 motorway (East Butterwick-Scunthorpe) B181 road road
United States Interstate 181 (former) U.S. Route 181 Alabama State Route 181 Arizona State Route 181 Arkansas Highway 181 California State Route 181 Connecticut Route 181 Florida State Road 181 (former) Georgia State Route 181 (former) Georgia State Route 181 Illinois Route 181 (former) Iowa Highway 181 (former) K-181 (Kansas highway) Kentucky Route 181 Louisiana Highway 181 Maine State Route 181 Maryland Route 181 Massachusetts Route 181 M-181 (Michigan highway) (former) Missouri Route 181 New Jersey Route 181 New Mexico State Road 181 New York State Route 181 (former) North Carolina Highway 181 Ohio State Route 181 Pennsylvania Route 181 South Carolina Highway 181 Tennessee State Route 181 Utah State Route 181 (former) Texas State Highway 181 (former) Texas State Highway Loop 181 Farm to Market Road 181 (Texas) Virginia State Route 181 Washington State Route 181 Wisconsin Highway 181
Territories: Puerto Rico Highway 181