List of highways numbered 18

International

• Asian Highway 18
• European route E18
• European route E018

  Canada

• Alberta Highway 18
• British Columbia Highway 18
• Manitoba Highway 18
• Ontario Highway 18
• Prince Edward Island Route 18
• Saskatchewan Highway 18

  China

• G18 Expressway

  Costa Rica

• National Route 18

  Czech Republic

• I/18 Highway; Czech: :cz:Silnice I/18|Silnice I/18

  India

• National Highway 18

  Iran

Japan

• Japan National Route 18
• Jōshin-etsu Expressway

  Korea, South

• National Route 18

  New Zealand

• New Zealand State Highway 18

  Russia

• M18 motorway running from Saint Petersburg to Murmansk

  South Africa

• N18 road

  Ukraine

• Highway M18

  United Kingdom

• British A18
• British M18

  United States

• U.S. Route 18
• New England Route 18
• Alabama State Route 18
• Arkansas Highway 18
• California State Route 18
• * County route A18
• * County Route E18
• * County Route G18
• * County Route J18
• * County Route S18
• Colorado State Highway 18
• Delaware Route 18
• Florida State Road 18
• * County Road 18
• * County Road 18
• * County Road 18
• Georgia State Route 18
• Hawaii Route 18
• Illinois Route 18
• Indiana State Road 18
• K-18
• Kentucky Route 18
• Louisiana Highway 18
• Maine State Route 18
• Maryland Route 18
• Massachusetts Route 18
• M-18
• Minnesota State Highway 18
• * County Road 18
• * County Road 18
• * County Road 18
• Mississippi Highway 18
• Missouri Route 18
• Nebraska Highway 18
• Nevada State Route 18
• New Hampshire Route 18
• New Jersey Route 18
• * New Jersey Route 18N
• * County Route 18
• New Mexico State Road 18
• New York State Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• * County Route 18
• North Carolina Highway 18
• North Dakota Highway 18
• Ohio State Route 18
• Oklahoma State Highway 18
• * Oklahoma State Highway 18B
• Oregon Route 18
• Pennsylvania Route 18
• South Carolina Highway 18
• South Dakota Highway 18
• Tennessee State Route 18
• Texas State Highway 18
• * Farm to Market Road 18
• * Ranch to Market Road 18
• Utah State Route 18
• Vermont Route 18
• Virginia State Route 18
• Washington State Route 18
• * Primary State Highway 18
• West Virginia Route 18
• Wisconsin Highway 18

• Guam Highway 18
• Puerto Rico Highway 18