The following highways are numbered 404:

Australia

- Victoria

Canada

• Manitoba Provincial Road 404
• Newfoundland and Labrador Route 404
• Ontario Highway 404

Costa Rica

• National Route 404

Israel

• Route 404 (Israel)

Japan

• Japan National Route 404

United Kingdom

• A404 road London - Maidenhead
• A404(M) Berkshire

United States

• Delaware Route 404
  • Delaware Route 404 Alternate (former)
  • Delaware Route 404 Business
  • Delaware Route 404 Truck
• Florida State Road 404
• Georgia State Route 404 (unsigned designation for Interstate 16)
  • Georgia State Route 404 Spur
• Iowa Highway 404 (unsigned designation for U.S. Route 75 Business)
• Maryland Route 404
  • Maryland Route 404 Alternate
  • Maryland Route 404 Business
• New Mexico State Road 404
• New York:
  • New York State Route 404
    • New York State Route 404 (former)
  • County Route 404 (Albany County, New York)
  • County Route 404 (Erie County, New York)
• Puerto Rico Highway 404
• Texas:
• Texas State Highway Loop 404
• Farm to Market Road 404 (former)
• Virginia State Route 404