The following highways are numbered 318:

Canada

• Nova Scotia Route 318
• Prince Edward Island Route 318
• Saskatchewan Highway 318

China

• China National Highway 318

Costa Rica

• National Route 318

Japan

• Japan National Route 318

United States

• Arkansas Highway 318
• Colorado State Highway 318
• Connecticut Route 318
• Florida:
  • Florida State Road 318 (former)
  • County Road 318, several roads in Florida
• Georgia State Route 318 (former)
• Indiana State Road 318 (former)
• Louisiana Highway 318
• Maryland Route 318
• Minnesota State Highway 318 (former)
• Montana Secondary Highway 318
• Nevada State Route 318
• New York:
  • New York State Route 318
  • County Route 318 (Wayne County, New York)
• Ohio State Route 318 (former)
• Pennsylvania Route 318
• Tennessee State Route 318
• Texas:
  • Texas State Highway 318 (former)
  • Farm to Market Road 318
• Utah State Route 318
• Virginia State Route 318
• Wyoming Highway 318

Other areas:

• Puerto Rico Highway 318
• U.S. Virgin Islands Highway 318