The following highways are numbered 231:
Canada Manitoba Provincial Road 231 Newfoundland and Labrador Route 231 Prince Edward Island Route 231 Quebec Route 231
Costa Rica National Route 231
India National Highway 231 (India)
Japan Japan National Route 231
Nigeria A231 highway (Nigeria)
United Kingdom road B231 road
United States U.S. Route 231 Arkansas Highway 231 California State Route 231 (former) Colorado State Highway 231 Florida State Road 231 Georgia State Route 231 K-231 (Kansas highway) Kentucky Route 231 (former) Maine State Route 231 Maryland Route 231 M-231 (Michigan highway) Minnesota State Highway 231 (former) Missouri Route 231 Montana Secondary Highway 231 Nevada State Route 231 New Mexico State Road 231 New York State Route 231 North Carolina Highway 231 Ohio State Route 231 Oregon Route 231 (former) Pennsylvania Route 231 South Dakota Highway 231 Tennessee State Route 231 Texas State Highway 231 Texas State Highway Loop 231 Texas State Highway Spur 231 Utah State Route 231 Virginia State Route 231 Wyoming Highway 231