List of highways numbered 21A
Route 21A, or Highway 21A, may refer to:
India
United States
- County Road 21A (Clay County, Florida)
- M-21A (Michigan highway)
- Nebraska Spur 21A
- New Jersey Route 21A
- New York State Route 21A
- * County Route 21A (Suffolk County, New York)
- * County Route 21A (Sullivan County, New York)
- * County Route 21A (Warren County, New York)
- Secondary State Highway 21A (Washington)