| Country: | JPN |
| Type: | National |
| Route: | 278 |
| Map Custom: | yes |
| Map Notes: | Japan National Route 278 highlighted in red |
| Length Km: | 114.3 |
| Length Ref: | [1] |
| Previous Type: | Route |
| Previous Route: | 277 |
| Next Type: | Route |
| Next Route: | 279 |
is a national highway on the island and prefecture of Hokkaido in northern Japan. The 114.3adj=onNaNadj=on highway connects Hakodate and Mori.