List of highways numbered 81
Route 81 or Highway 81 may refer to:
International
Australia
- Escort Way
- Mulligan Highway and Peninsula Developmental Road – Queensland State Route 81
Canada
Greece
India
Korea, South
Mexico
Philippines
United States
- Interstate 81
- * Interstate 81E
- * Interstate 81S
- U.S. Route 81
- Alabama State Route 81
- * County Route 81
- Arizona State Route 81
- Arkansas Highway 81
- California State Route 81
- Connecticut Route 81
- Florida State Road 81
- * County Road 81A (Holmes County, Florida)
- Georgia State Route 81
- Idaho State Highway 81
- Illinois Route 81
- Iowa Highway 81
- Kentucky Route 81
- Louisiana Highway 81
- * Louisiana State Route 81
- Maryland Route 81
- Massachusetts Route 81
- M-81 (Michigan highway)
- Minnesota:
- * Minnesota State Highway 81 (1934)
- * Minnesota State Highway 81 (pre-1988)
- Missouri Route 81
- Montana Highway 81
- Nebraska Highway 81
- Nevada State Route 81
- New Jersey Route 81
- * County Route 81 (Bergen County, New Jersey)
- New Mexico State Road 81
- New York State Route 81
- * County Route 81A (Cayuga County, New York)
- **County Route 81C (Cayuga County, New York)
- * County Route 81 (Chautauqua County, New York)
- * County Route 81 (Dutchess County, New York)
- * County Route 81 (Essex County, New York)
- * County Route 81 (Madison County, New York)
- * County Route 81 (Montgomery County, New York)
- * County Route 81 (Oneida County, New York)
- * County Route 81 (Rockland County, New York)
- * County Route 81 (Suffolk County, New York)
- * County Route 81 (Sullivan County, New York)
- North Carolina Highway 81
- Country Road 81
- Ohio State Route 81
- Oklahoma State Highway 81A
- Pennsylvania Route 81
- Rhode Island Route 81
- South Carolina Highway 81
- South Dakota Highway 81
- Tennessee State Route 81
- *Tennessee State Route 81A
- Texas State Highway 81
- * Texas State Highway Loop 81
- * Farm to Market Road 81
- Utah State Route 81
- Virginia State Route 81
- West [Virginia Route 81 (1925–1941)]
- * West Virginia Route 81 (1960–1961)
- Wisconsin Highway 81