List of highways numbered 99
International
- European route E99
Australia
- Springbrook Road, Queensland
Canada
- British Columbia Highway 99
- Ontario Highway 99
- Saskatchewan Highway 99
China
- G99 Expressway
Greece
- EO99 road
India
- National Highway 99 (India)
Iran
- Road 99
Israel
- Highway 99 (Israel)
New Zealand
- New Zealand [State Highway 99]
Poland
United States
- Interstate 99
- * Interstate 99 (Delaware-North Carolina)
- U.S. Route 99
- * U.S. Route 99T
- Alabama State Route 99
- * County Route 99
- Arizona State Route 99
- Arkansas Highway 99
- California State Route 99
- Connecticut Route 99
- Florida State Road 99
- * Road 99 (Escambia County, Florida)">Road 99 (Iran)">Road 99 (Escambia County, Florida)
- ** County Road 99A (Escambia County, Florida)
- Georgia State Route 99
- Hawaii Route 99
- Idaho State Highway 99
- Illinois Route 99
- Iowa Highway 99
- * County Road 99 (Des Moines County, Iowa)
- * County Road 99 (Louisa County, Iowa)
- K-99 (Kansas highway)
- Kentucky Route 99
- Louisiana Highway 99
- Maine State Route 99
- Maryland Route 99
- Massachusetts Route 99
- M-99 (Michigan highway)
- Minnesota State Highway 99
- Missouri Route 99
- * Missouri Route 99 (1929)
- Nebraska Highway 99
- County Route 99 (Bergen County, New Jersey)
- New Mexico State Road 99
- New York State Route 99
- * County Route 99 (Dutchess County, New York)
- * County Route 99 (Herkimer County, New York)
- * County Route 99 (Madison County, New York)
- * County Route 99 (Montgomery County, New York)
- * County Route 99 (Onondaga County, New York)
- * County Route 99 (Orleans County, New York)
- * County Route 99 (Saratoga County, New York)
- * County Route 99 (Schenectady County, New York)
- * County Route 99 (Steuben County, New York)
- * County Route 99 (Suffolk County, New York)
- * County Route 99 (Westchester County, New York)
- North Carolina Highway 99
- Ohio State Route 99
- Oklahoma State Highway 99
- * Oklahoma State Highway 99A
- Oregon Route 99
- * Oregon Route 99E
- * Oregon Route 99W
- Pennsylvania Route 99
- Rhode Island Route 99
- South Carolina Highway 99
- Tennessee State Route 99
- Texas State Highway 99
- * Texas State Highway Spur 99 (1940–1966)
- * Texas State Highway Spur 99 (1981–1984)
- * Farm to Market Road 99
- Utah State Route 99
- Virginia State Route 99
- Washington State Route 99
- * Washington State Route 99T
- West Virginia Route 99
- Wisconsin Highway 99