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
Iran
- Road 99
Israel
- Highway 99
New Zealand
- New Zealand State Highway 99
Poland
United States
- Interstate 99
- * Interstate 99
- 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
- * County Road 99
- ** County Road 99A
- Georgia State Route 99
- Hawaii Route 99
- Idaho State Highway 99
- Illinois Route 99
- Iowa Highway 99
- * County Road 99
- * County Road 99
- K-99
- Kentucky Route 99
- Louisiana Highway 99
- Maine State Route 99
- Maryland Route 99
- Massachusetts Route 99
- M-99
- Minnesota State Highway 99
- Missouri Route 99
- * Missouri Route 99
- Nebraska Highway 99
- County Route 99
- New Mexico State Road 99
- New York State Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- * County Route 99
- 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
- * Texas State Highway Spur 99
- * 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