The North Fork John Day River is a 107-mile (172 km) tributary of the John Day River in the U.S. state of Oregon. It begins in Grant County about 20 miles (32 km) northwest of Baker City near the crest of the Blue Mountains. It flows generally west to the community of Dale on U.S. Route 395, then southwest through the city of Monument to the unincorporated community of Kimberly, where it meets the main stem of the John Day River.