List of highways numbered 18
Route 18, or Highway 18, may refer to:
International
Argentina
*Australia
Canada
- Alberta Highway 18
- British Columbia Highway 18
- Manitoba Highway 18
- Ontario Highway 18
- Prince Edward Island Route 18
- Saskatchewan Highway 18
China
Costa Rica
Cuba
Czech Republic
- I/18 Highway; Czech: Silnice I/18
Greece
India
Ireland
Italy
Japan
Korea, South
New Zealand
Paraguay
- [Image:R18-PY.svg|20px|] National Route 18
Poland
Russia
- M18 motorway (Russia) running from Saint Petersburg to Murmansk
South Africa
Ukraine
United Kingdom
United States
- U.S. Route 18
- New England Route 18
- Alabama State Route 18
- * County Route 18
- 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)
- 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
- Illinois Route 18
- Indiana State Road 18
- K-18 (Kansas highway)
- Kentucky Route 18
- Louisiana Highway 18
- Maine State Route 18
- 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
- New Hampshire Route 18
- New Jersey Route 18
- * New Jersey Route 18N
- * 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
- 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 (Washington)
- West Virginia Route 18
- Wisconsin Highway 18