The following highways are numbered 308:

Brazil

• BR-308

Canada

• Manitoba Provincial Road 308
• Nova Scotia Route 308
• Prince Edward Island Route 308
• Saskatchewan Highway 308

China

• China National Highway 308

Costa Rica

• National Route 308

Japan

• Japan National Route 308

United States

• Arkansas Highway 308
  • Arkansas Highway 308 Business
  • Arkansas Highway 308 Spur
• Florida:
  • Florida State Road 308 (former)
  • County Road 308 (Putnam County, Florida)
  • County Road 308B (Putnam County, Florida)
• Georgia State Route 308
• Kentucky Route 308
• Louisiana Highway 308
  • 
    Louisiana Highway 308 Spur (former)
• Maryland Route 308 (unsigned)
• Minnesota State Highway 308
• Montana Secondary Highway 308
• New York:
  • New York State Route 308
  • County Route 308 (Albany County, New York)
  • County Route 308 (Erie County, New York)
  • County Route 308 (Wayne County, New York)
• North Carolina Highway 308
• Ohio State Route 308
• Pennsylvania Route 308
• South Carolina Highway 308
• Tennessee State Route 308
• Texas:
  • Texas State Highway 308
  • Texas State Highway Loop 308
  • Farm to Market Road 308
• Utah State Route 308 (former)
• Virginia State Route 308
• Washington State Route 308

Other areas:

• Puerto Rico Highway 308
• U.S. Virgin Islands Highway 308