The following highways are numbered 320:
Canada Newfoundland and Labrador Route 320 Nova Scotia Route 320 Saskatchewan Highway 320
China China National Highway 320
Costa Rica National Route 320
India National Highway 320 (India)
Japan Japan National Route 320
United States U.S. Route 320 (former) Arkansas Highway 320 Connecticut Route 320 Florida State Road 320 County Road 320 (Florida) Georgia State Route 320 Hawaii Route 320 Kentucky Route 320 Louisiana Highway 320 Maryland Route 320 Montana Secondary Highway 320 Nevada State Route 320 New Mexico State Road 320 New York State Route 320 Ohio State Route 320 Pennsylvania Route 320 Puerto Rico Highway 320 Tennessee State Route 320 Texas: Texas State Highway 320 Texas State Highway Loop 320 (former) Farm to Market Road 320 Utah State Route 320 Virginia State Route 320 Wyoming Highway 320