List of highways numbered 303

Canada

• New Brunswick Route 303
• Nova Scotia Route 303
• Prince Edward Island Route 303
• Quebec Route 303
• Saskatchewan Highway 303

  China

• China National Highway 303

  Costa Rica

• National Route 303

  India

• National Highway 303

  Japan

• Japan National Route 303

  United Kingdom

• A303 road

  United States

• Arizona State Route 303
• Arkansas Highway 303
• Georgia State Route 303
• Indiana State Road 303
• Kentucky Route 303
• Louisiana Highway 303
• Maryland Route 303
• Minnesota State Highway 303
• New Jersey Route 303
• New York:
• * New York State Route 303
• * County Route 303
• * County Route 303
• * County Route 303
• North Carolina Highway 303
• Ohio State Route 303
• Pennsylvania Route 303
• South Carolina Highway 303
• Tennessee State Route 303
• Texas:
• * Texas State Highway 303
• * Texas State Highway Spur 303
• * Farm to Market Road 303
• * Urban Road 303
• Utah State Route 303
• Virginia State Route 303
• Washington State Route 303

• Puerto Rico Highway 303
• U.S. Virgin Islands Highway 303