The following highways are numbered 312:

Canada

• Manitoba Provincial Road 312
• Nova Scotia Route 312
• Prince Edward Island Route 312
• Saskatchewan Highway 312

China

• China National Highway 312

Costa Rica

• National Route 312

Japan

• Japan National Route 312

United States

• U.S. Route 312 (former)
• Arkansas Highway 312
• Florida State Road 312
• Georgia State Route 312 (former)
• Indiana State Road 312
• Kentucky Route 312
• Louisiana Highway 312
• Maryland Route 312
• Minnesota State Highway 312 (former)
• New Mexico State Road 312
• New York:
  • New York State Route 312
  • New York State Route 312 (former)
  • County Route 312 (Albany County, New York)
  • County Route 312 (Wayne County, New York)
• Ohio State Route 312
• Pennsylvania Route 312 (former)
• Puerto Rico Highway 312
• Tennessee State Route 312
• Texas:
  • Texas State Highway 312 (proposed)
  • Texas State Highway Spur 312
• Farm to Market Road 312
• Utah State Route 312
• Virginia State Route 312
• Wisconsin Highway 312
• Wyoming Highway 312