The following highways are numbered 300:
Australia Midland Highway (Victoria) Melba Highway (Victoria)
Canada Manitoba Provincial Road 300
Cuba
Santiago de las Vegas–Cuatro Caminos Road (2–300)
Japan Japan National Route 300
Korea, South Daejeon Southern Ring Expressway
Turkey , a west–east state road in Turkey running from Çeşme, İzmir Province to Kapıköy at the Iranian border.
United Kingdom A300 road
United States Arkansas Highway 300 Colorado State Highway 300 Delaware Route 300 Florida State Road 300 Georgia State Route 300 Georgia State Route 300 Connector Georgia State Route 300 (former) Iowa Highway 300 (former) Kentucky Route 300 Louisiana Highway 300 Maryland Route 300 Minnesota State Highway 300 (former) Montana Secondary Highway 300 New Jersey Route 300 (former) New Mexico State Road 300 New York State Route 300 Ohio State Route 300 Pennsylvania Route 300 (official designation for Pennsylvania Route 283) Puerto Rico Highway 300 South Carolina Highway 300 Tennessee State Route 300 (unsigned) Texas State Highway 300 Texas State Highway Spur 300 Farm to Market Road 300 Utah State Route 300 (former) Virginia State Route 300 Washington State Route 300