| Country: | JPN |
| Type: | National |
| Route: | 366 |
| Map Custom: | yes |
| Length Km: | 20.1 |
| Length Ref: | [1] |
| Established: | 1975 |
| Direction A: | West |
| Terminus A: | in Handa, Aichi |
| Direction B: | East |
| Terminus B: | in Atsuta-ku, Nagoya |
| Previous Type: | Route |
| Previous Route: | 365 |
| Next Type: | Route |
| Next Route: | 367 |
National Route 366 is a national highway of Japan connecting Handa, Aichi and Atsuta-ku, Nagoya within Japan, with a total length of 20.1 km (12.49 mi).