List of highways numbered 251

Canada

• Manitoba Provincial Road 251
• Prince Edward Island Route 251
• Quebec Route 251

  Costa Rica

• National Route 251

  Japan

• Japan National Route 251

  Korea, South

• Honam Expressway Branch

  United States

• Alabama State Route 251
• California State Route 251
• Florida State Road 251
• Georgia State Route 251
• Illinois Route 251
• K-251
• Kentucky Route 251
• Minnesota State Highway 251
• Montana Secondary Highway 251
• New York State Route 251
• Ohio State Route 251
• Oklahoma State Highway 251A
• Oregon Route 251
• Pennsylvania Route 251
• South Dakota Highway 251
• Tennessee State Route 251
• Texas State Highway 251
• * Farm to Market Road 251
• Utah State Route 251
• Virginia State Route 251
• Washington State Route 251
• West Virginia Route 251
• Wyoming Highway 251

• Puerto Rico Highway 251