The following highways are numbered 203:
Canada Manitoba Provincial Road 203 Newfoundland and Labrador Route 203 Nova Scotia Route 203 Prince Edward Island Route 203 Quebec Route 203
Chile Route 203-CH in Los Ríos Region
China China National Highway 203
Costa Rica National Route 203
India National Highway 203 (India)
Japan Japan National Route 203
Belgium Belgium B203
Thailand Thailand Route 203
United Kingdom road B203 road
United States Alabama State Route 203 California State Route 203 Connecticut Route 203 Georgia State Route 203 Illinois Route 203 Indiana State Road 203 Iowa Highway 203 (former) K-203 (Kansas highway) Kentucky Route 203 Maine State Route 203 (former) Massachusetts Route 203 M-203 (Michigan highway) Montana Secondary Highway 203 New Mexico State Road 203 New York State Route 203 Ohio State Route 203 Oregon Route 203 Pennsylvania Route 203 (former) South Carolina Highway 203 South Dakota Highway 203 Tennessee State Route 203 Texas State Highway 203 Texas State Highway Spur 203 Utah State Route 203 Virginia State Route 203 Washington State Route 203 Territories Puerto Rico Highway 203