List of highways numbered 66

Australia

• Barkly Highway
• Riddoch Highway

  Canada

• Alberta Highway 66
• Highway 66

  Finland

• Kantatie 66

  France

• A66 autoroute

  Germany

• Bundesautobahn 66

  Greece

• Greek National Road 66, a national highway connecting Nemea with Levidi via Skoteini

  Hungary

• 66-os főút

  India

• National Highway 66

  Ireland

• N66

  Israel

• Highway 66

  Malaysia

• Malaysia Federal Route 66

  Slovakia

• Road 66, from Slovak - Hungarian border at Šahy to Tatras mountain

  Spain

• Autovía A-66

  United Arab Emirates

• E 66

  United Kingdom

• A66 road
• M66 motorway

  United States

• Interstate 66, a highway connecting Interstate 81 in Virginia to Washington, D.C.
• * Interstate 66, a former proposed highway to connect Kansas with Kentucky
• U.S. Route 66, the most common meaning. Since 1985, when US 66 was decommissioned, several states where US 66 passed have re-commissioned part of the former route in that state as a state route 66. In the list of state routes 66 below, those marked with an asterisk have a connection with the former US 66.
• Alabama State Route 66
• Arizona State Route 66*
• Arkansas Highway 66
• California State Route 66*
• Colorado State Highway 66
• Connecticut Route 66
• Florida State Road 66
• Georgia State Route 66
• Hawaii Route 66
• Idaho State Highway 66
• Illinois Route 66 is now Illinois 126*
• Indiana State Road 66
• Iowa Highway 66
• K-66 *
• Kentucky Route 66
• Louisiana Highway 66
• Maryland Route 66
• Massachusetts Route 66
• M-66
• Minnesota State Highway 66
• * County Road 66
• Missouri Route 66*
• Missouri Route 66, a pre-1926 highway not connected to US 66
• Montana Highway 66
• Nebraska Highway 66
• * Nebraska Spur 66A
• * Nebraska Spur 66C
• * Nebraska Spur 66D
• * Nebraska Spur 66E
• Nevada State Route 66
• New Jersey Route 66
• New York State Route 66
• *County Route 66A
• **County Route 66B
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• * County Route 66
• *County Route 66A
• North Carolina Highway 66
• North Dakota Highway 66
• Ohio State Route 66
• Oklahoma State Highway 66*
• * Oklahoma State Highway 66B*
• Oregon Route 66
• Pennsylvania Route 66
• Puerto Rico Highway 66
• South Carolina Highway 66
• Tennessee State Route 66
• Texas State Highway 66
• * Texas State Highway Loop 66
• * Texas State Highway Spur 66
• * Farm to Market Road 66
• * Texas Park Road 66
• U.S. Virgin Islands Highway 66
• Utah State Route 66
• Vermont Route 66
• Virginia State Route 66
• West Virginia Route 66
• Wisconsin Highway 66