List of highways numbered 21

For roads named A21 see ; List of A21 roads
Route 21, or Highway 21, can refer to:

International

• European route E21

Austria

• Wiener Außenring Autobahn

Cambodia

• National Road 21 (Cambodia)

Canada

• Alberta Highway 21
• British Columbia Highway 21
• Manitoba Highway 21
• Newfoundland and Labrador Route 21
• Ontario Highway 21
• Prince Edward Island Route 21
• Saskatchewan Highway 21

Czech Republic

• I/21 Highway; Czech: Silnice I/21

India

21

National Highway 21 (India)

Iran

• Road 21

Japan

• Japan National Route 21

Korea, South

• National Route 21

New Zealand

• New Zealand State Highway 21

Turkey

• , a motorway in Turkey running from Kemerhisar, Niğde Province to Tarsus, Mersin Province.

United Kingdom

• British A21 (Hastings-London)

United States

• U.S. Route 21
• Alabama State Route 21
• Arkansas Highway 21
  • Arkansas Highway 21E (former)
  • Arkansas Highway 21W (former)
• California State Route 21 (former)
• Colorado State Highway 21
• Connecticut Route 21
• Florida State Road 21
• Georgia State Route 21
• Hawaii Route 21 (former)
• Idaho State Highway 21
• Illinois Route 21
• Indiana State Road 21 (former)
• Iowa Highway 21
• Kentucky Route 21
• Louisiana Highway 21
• Maryland Route 21
• Massachusetts Route 21
• M-21 (Michigan highway)
• Minnesota State Highway 21
• Mississippi Highway 21
• Missouri Route 21
• Montana Highway 21
• Nebraska Highway 21
• Nevada State Route 21 (former)
• New Jersey Route 21
• New Mexico State Road 21
• New York State Route 21
• North Carolina Highway 21 (former)
• North Dakota Highway 21
• Ohio State Route 21
• Pennsylvania Route 21
• South Dakota Highway 21
• Tennessee State Route 21
• Texas State Highway 21
  • Texas State Highway Loop 21
  • Texas Farm to Market Road 21
  • Texas Park Road 21
• Utah State Route 21
• Virginia State Route 21 (former)
• Washington State Route 21
• Wisconsin Highway 21

Other areas:

• Puerto Rico Highway 21