The following highways are numbered 345:
Australia - Victoria
Canada Manitoba Provincial Road 345 New Brunswick Route 345 Newfoundland and Labrador Route 345 Prince Edward Island Route 345 Quebec Route 345
Japan Japan National Route 345
Nigeria A345 highway (Nigeria)
United Kingdom A345 road, Marlborough, Wiltshire to Salisbury, Wiltshire
United States 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