Route 171, or Highway 171, may refer to:

Canada

• Prince Edward Island Route 171
• Quebec Route 171

Costa Rica

• National Route 171

Ireland

• R171 road

Israel

• Route 171 (Israel)

Japan

• Japan National Route 171

Korea, South

• Expressway 171
  • Osan–Hwaseong Expressway
  • Yongin–Seoul Expressway

United States

• U.S. Route 171
• Alabama State Route 171
• Arkansas Highway 171
• California State Route 171 (former)
• Connecticut Route 171
• Florida State Road 171 (former)
• Georgia State Route 171
• Illinois Route 171
• K-171 (Kansas highway)
• Kentucky Route 171
• Maine State Route 171
• Maryland Route 171
• M-171 (Michigan highway)
• Minnesota State Highway 171
• Missouri Route 171
• Nevada State Route 171
• New Hampshire Route 171
• New Jersey Route 171
• New Mexico State Road 171
• New York State Route 171
• North Carolina Highway 171
• Ohio State Route 171
• Oklahoma State Highway 171
• Pennsylvania Route 171
• South Carolina Highway 171
• Tennessee State Route 171
• Texas State Highway 171
  • Business State Highway 171-E (Texas)
  • Texas State Highway Loop 171
  • Farm to Market Road 171
• Utah State Route 171
• Virginia State Route 171
• Washington State Route 171
• Wisconsin Highway 171
• Wyoming Highway 171

Territories

• Puerto Rico Highway 171