| Country: | JPN |
| Type: | National |
| Route: | 238 |
| Map Custom: | yes |
| Map Notes: | Japan National Route 238 highlighted in red |
| Length Km: | 319.6 |
| Length Ref: | [1] |
| Direction A: | East |
| Terminus A: | in Abashiri |
| Direction B: | West |
| Terminus B: | in Wakkanai |
| Previous Type: | Route |
| Previous Route: | 237 |
| Next Type: | Route |
| Next Route: | 239 |
is the northernmost of the national highways of Japan. It connects the cities of Abashiri and Wakkanai in the northern part of the island and prefecture of Hokkaido in northern Japan.
On 18 May 1953, the highway was established as Second Class National Highway 238 by the Cabinet of Japan.[2] It was re-designated as General National Route 238 on 1 April 1965.[3] A curve of the road was made less sharp in Yubetsu on 1 April 2018, this shortened the total length of the highway by 30m (100feet).[4]
The route lies entirely within Hokkaido.