Route 18, or Highway 18, may refer to:
International Asian Highway 18 European route E18 European route E018
Argentina
Australia Waterfall Way
Canada Alberta Highway 18 British Columbia Highway 18 Manitoba Highway 18 Ontario Highway 18 (former) Prince Edward Island Route 18 Saskatchewan Highway 18
China G18 Expressway
Costa Rica National Route 18
Cuba Highway 2–18
Czech Republic I/18 Highway; Czech: Silnice I/18
Greece EO18 road (1963–1995; now numbered the EO19)
India National Highway 18 (India)
Iran
Ireland M18 motorway (Ireland) N18 road (Ireland)
Italy Autostrada A18 State road 18
Japan Japan National Route 18 Jōshin-etsu Expressway
Korea, South National Route 18
Malaysia
Malaysia Federal Route 18
New Zealand New Zealand State Highway 18
Paraguay National Route 18
Poland Motorway A18 National road 18
Russia M18 motorway (Russia) running from Saint Petersburg to Murmansk
South Africa N18 road (South Africa)
Ukraine Highway M18 (Ukraine)
United Kingdom British A18 (Doncaster-Ludborough) British M18 (Thurcroft-Rawcliffe)
United States U.S. Route 18 New England Route 18 (former) Alabama State Route 18 County Route 18 (Lee County, Alabama) Arkansas Highway 18 California State Route 18 County route A18 (California) County Route E18 (California) County Route G18 (California) County Route J18 (California) County Route S18 (California) Colorado State Highway 18 (pre-1968) (former) Delaware Route 18 Florida State Road 18 County Road 18 (Bradford County, Florida) County Road 18 (Columbia County, Florida) County Road 18 (Union County, Florida) Georgia State Route 18 Hawaii Route 18 (former) Illinois Route 18 Indiana State Road 18 K-18 (Kansas highway) Kentucky Route 18 Louisiana Highway 18 Maine State Route 18 (former) Maryland Route 18 Massachusetts Route 18 M-18 (Michigan highway) Minnesota State Highway 18 County Road 18 (Anoka County, Minnesota) County Road 18 (Scott County, Minnesota) County Road 18 (Washington County, Minnesota) Mississippi Highway 18 Missouri Route 18 Nebraska Highway 18 Nevada State Route 18 (former) New Hampshire Route 18 New Jersey Route 18 New Jersey Route 18N (former) County Route 18 (Monmouth County, New Jersey) New Mexico State Road 18 New York State Route 18 County Route 18 (Allegany County, New York) County Route 18 (Chautauqua County, New York) County Route 18 (Columbia County, New York) County Route 18 (Dutchess County, New York) County Route 18 (Erie County, New York) County Route 18 (Essex County, New York) County Route 18 (Herkimer County, New York) County Route 18 (Onondaga County, New York) County Route 18 (Ontario County, New York) County Route 18 (Orange County, New York) County Route 18 (Orleans County, New York) County Route 18 (Otsego County, New York) County Route 18 (Rensselaer County, New York) County Route 18 (Schoharie County, New York) County Route 18 (Schuyler County, New York) County Route 18 (Steuben County, New York) County Route 18 (Suffolk County, New York) County Route 18 (Tioga County, New York) County Route 18 (Washington County, New York) County Route 18 (Westchester County, New York) County Route 18 (Yates County, New York) 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 (former) Tennessee State Route 18 Texas State Highway 18 Farm to Market Road 18 Ranch to Market Road 18 (former) Utah State Route 18 Vermont Route 18 Virginia State Route 18 Washington State Route 18 Primary State Highway 18 (Washington) (former) West Virginia Route 18 Wisconsin Highway 18 (former)
Territories Guam Highway 18 Puerto Rico Highway 18
Zambia M18 road (Zambia)
See also List of A18 roads List of M18 roads List of highways numbered 18A List of highways numbered 18B List of highways numbered 18C List of highways numbered 18D List of highways numbered 18E List of highways numbered 18F Highway 18, a Golf Channel series similar to The Amazing Race