| Country: | JPN |
| Type: | National |
| Route: | 104 |
| Map Custom: | yes |
| Map Notes: | Japan National Route 104 highlighted in red |
| Length Km: | 126.3 |
| Length Ref: | [1] |
| Established: | 1953 |
| Direction A: | East |
| Terminus A: | in Hachinohe, Aomori |
| Direction B: | West |
| Terminus B: | in Ōdate, Akita |
| Previous Type: | Route |
| Previous Route: | 103 |
| Next Type: | Route |
| Next Route: | 105 |
is a national highway of Japan connecting the cities of Hachinohe in southeastern Aomori Prefecture and Ōdate in northern Akita Prefecture in northern Japan. It travels east to west and has a total length of 126.3km (78.5miles).
National Route 104 has a total length of 126.3km (78.5miles). From its junction with National Route 454 in Hachinohe to the beginning of its unsigned concurrency with National Route 103 in Kazuno, the highway is known as the Shirahagi Line.[2]
National Route 104 was established by the Cabinet of Japan as a second-class national highway in 1953. The system of different classes of national highways was abolished in 1970, in turn, the highway was designated as National Route 104.[3]
All junctions listed are at-grade intersections unless noted otherwise.