| State: | PR |
| Type: | PR |
| Route: | 6685 |
| Maint: | Puerto Rico DTPW |
| Length Km: | 11.9 |
| Direction A: | South |
| Terminus A: | in Hato Viejo–Cordillera |
| Junction: |
|
| Direction B: | North |
| Terminus B: | in Manatí barrio-pueblo |
| Municipalities: | Ciales, Manatí |
| Previous Type: | Sec |
| Previous Route: | 6633 |
| Next Type: | Ter |
| Next Route: | 6690 |
Puerto Rico Highway 6685 (PR-6685) is a rural highway in Puerto Rico that runs south to north, connecting the towns of Ciales and Manatí on Puerto Rico's north coast.[1] It runs slightly parallel to Puerto Rico Highway 149 until it ends at Puerto Rico Highway 2 in Manatí.[2] It has a junction with PR-149 in Ciales and with Puerto Rico Highway 642 in Río Arriba Saliente barrio, in Manatí.[3]