| State: | TAM |
| Type: | FH |
| Route: | 81 |
| Maint: | Secretariat of Communications and Transportation |
| Length Km: | 89.00 |
| Length Round: | 2 |
| Length Ref: | [1] |
| Direction A: | North |
| Terminus A: | in Llera de Canales, Tamaulipas[2] |
| Junction: | in Ignacio Zaragoza |
| Direction B: | South |
| Terminus B: | in González, Tamaulipas |
| Previous Type: | FH |
| Previous Route: | 80 |
| Next Type: | FH |
| Next Route: | 82 |
Federal Highway 81 (Carretera Federal 81) connects Llera de Canales, Tamaulipas, to González, Tamaulipas.[3]