List of highways numbered 166

The following highways are numbered 166:

Canada

 * Prince Edward Island Route 166

India

 * NH166-IN.svg National Highway 166 (India)

Japan

 * Japanese National Route Sign 0166.svg Japan National Route 166

United States

 * US 166.svg U.S. Route 166
 * Alabama 166.svg Alabama State Route 166
 * Arizona 166.svg Arizona State Route 166 (former)
 * California 166.svg California State Route 166
 * Connecticut Highway 166.svg Connecticut Route 166
 * Florida 166.svg Florida State Road 166
 * Georgia 166.svg Georgia State Route 166
 * Illinois 166.svg Illinois Route 166
 * Indiana 166.svg Indiana State Road 166
 * Elongated circle 166.svg Kentucky Route 166
 * MA Route 166.svg Maine State Route 166
 * MA Route 166A.svg Maine State Route 166A
 * MD Route 166.svg Maryland Route 166
 * M-166.svg M-166 (Michigan highway)
 * Nevada 166.svg Nevada State Route 166 (former)
 * Ellipse sign 166.svg New Jersey Route 166
 * New Mexico 166.svg New Mexico State Road 166
 * NY-166.svg New York State Route 166
 * OH-166.svg Ohio State Route 166
 * Oklahoma State Highway 166.svg Oklahoma State Highway 166
 * PA-166.svg Pennsylvania Route 166
 * Secondary Tennessee 166.svg Tennessee State Route 166
 * Texas 166.svg Texas State Highway 166
 * Texas Loop 166.svg Texas State Highway Loop 166
 * Utah SR 166.svg Utah State Route 166 (former)
 * Virginia 166.svg Virginia State Route 166
 * WA-166.svg Washington State Route 166
 * WIS 166.svg Wisconsin Highway 166 (former)
 * Territories:
 * PR secondary 166.svg Puerto Rico Highway 166