List of highways numbered 420

Route 420 or Highway 420 may refer to:

Australia

 * Bass Highway (Victoria)
 * South Gippsland Freeway
 * South Gippsland Highway
 * Bass Highway
 * Phillip Island Road

Canada

 * Ontario 420.svg Ontario Highway 420
 * New Brunswick Route 420
 * Newfoundland and Labrador Route 420

Ireland

 * R420 road

Japan

 * Japanese National Route Sign 0420.svg Japan National Route 420

Norway

 * Riksvei 420.svg Norwegian County Road 420

Spain

 * N-420

United Kingdom

 * UK road A420.svg A420 road (Bristol to Oxford)

United States

 * I-420.svg Interstate 420 (multiple highways) (former)
 * US 420.svg U.S. Route 420
 * Florida 420.svg Florida State Road 420 (former)
 * Orange County Road 420 FL.svg County Road 420 (Orange County, Florida)
 * Louisiana 420.svg Louisiana Highway 420
 * Indiana 420.svg Indiana State Road 420 (now Interstate 94).
 * New Mexico 420.svg New Mexico State Road 420
 * NY-420.svg New York State Route 420
 * OH-420.svg Ohio State Route 420
 * PA-420.svg Pennsylvania Route 420
 * Ellipse sign 420.svg Puerto Rico Highway 420
 * South Carolina 420.svg South Carolina Highway 420
 * Secondary Tennessee 420.svg Tennessee State Route 420
 * Texas FM 420.svg Farm to Market Road 420
 * Virginia 420.svg Virginia State Route 420
 * Elongated circle 420.svg Kentucky State Route 420