The following highways are numbered 84.

• AH84 Asian Highway 84
• E84 European route E84

• Golden Highway
• Wills Developmental Road (Queensland)

• EO84 road

• Road 84

• Gukjido 84

• New Zealand State Highway 84

• Interstate 84 (Oregon–Utah)
• Interstate 84 (Pennsylvania–Massachusetts)
• U.S. Route 84
• Arizona State Route 84
  • Arizona State Route 84A
• Arkansas Highway 84
• California State Route 84
• Colorado State Highway 84 (1923-1968) (former)
• Florida State Road 84
• Georgia State Route 84
• Illinois Route 84
• K-84 (Kansas highway)
• Kentucky Route 84
• Maryland Route 84
• M-84 (Michigan highway)
• Minnesota State Highway 84
  • County Road 84 (Anoka County, Minnesota)
• Missouri Route 84
• Montana Highway 84
• Nebraska Highway 84
• Nevada State Route 84 (former)
• New Hampshire Route 84
• New Jersey Route 84
  • County Route 84 (Bergen County, New Jersey)
• New York State Route 84 (former)
  • County Route 84 (Broome County, New York)
  • County Route 84 (Chautauqua County, New York)
  • County Route 84 (Chemung County, New York)
  • County Route 84 (Dutchess County, New York)
  • County Route 84 (Erie County, New York)
  • County Route 84 (Essex County, New York)
  • County Route 84 (Greene County, New York)
  • County Route 84 (Jefferson County, New York)
  • County Route 84 (Livingston County, New York)
  • County Route 84 (Madison County, New York)
  • County Route 84 (Monroe County, New York)
  • County Route 84 (Onondaga County, New York)
  • County Route 84 (Rensselaer County, New York)
  • County Route 84 (Rockland County, New York)
  • County Route 84 (Schenectady County, New York)
  • County Route 84 (Suffolk County, New York)
• North Carolina Highway 84
• Ohio State Route 84
• Oklahoma State Highway 84
• Pennsylvania Route 84 (former)
• Rhode Island Route 84 (former)
• Tennessee State Route 84
• Texas State Highway 84
  • Texas State Highway Loop 84
  • Texas State Highway Spur 84 (former)
  • Farm to Market Road 84
  • Urban Road 84 (former)
• Utah State Route 84 (former)
• Virginia State Route 84
• West Virginia Route 84
• Wisconsin Highway 84 (former)

• A84