State Road 378 (NM 378) is a 3.4-mile-long (5.5 km) state highway in far northern New Mexico.

Beginning at a junction with NM 522, NM 378 heads generally west through the small town of Cerro and officially ends shortly thereafter at the boundary of BLM lands.

The paved surface continues a few miles further under a different designation to end at the BLM's Wild Rivers National Recreation Area.

The entire route is in Taos County.

Geographic data related to New Mexico State Road 378 at OpenStreetMap