The following highways are numbered 345:

- Victoria

• Manitoba Provincial Road 345
• New Brunswick Route 345
• Newfoundland and Labrador Route 345
• Prince Edward Island Route 345
• Quebec Route 345

• Japan National Route 345

• A345 highway (Nigeria)

• Interstate 345 (unsigned)
• Arkansas Highway 345
• Florida:
  • Florida State Road 345
  • County Road 345 (Levy County, Florida)
• New York State Route 345
• North Carolina Highway 345
• Ohio State Route 345
• Pennsylvania Route 345
• Puerto Rico Highway 345
• Texas:
  • Texas State Highway 345
  • Texas State Highway Loop 345
• Virginia State Route 345
  • Virginia State Route 345 (former)
• Wyoming Highway 345