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 Highway 420
- New Brunswick Route 420
- Newfoundland and Labrador Route 420
Ireland
- R420 road
Japan
- Japan [National Route 420]
Norway
- Norwegian [County Road 420]
Spain
- N-420
United Kingdom
- A420 road (Bristol to Oxford)
United States
- Interstate 420
- U.S. Route 420
- Florida [State Road 420]
- County Road 420 (Orange County, Florida)
- Louisiana Highway 420
- Indiana State Road 420.
- New Mexico State Road 420
- New York State Route 420
- Ohio State Route 420
- Pennsylvania Route 420
- Puerto Rico Highway 420
- South Carolina Highway 420
- Tennessee State Route 420
- Farm to Market Road 420
- Virginia State Route 420
- Kentucky State Route 420