| Country: | JPN |
| Type: | National |
| Route: | 146 |
| Image Notes: | Route 146 in Karuizawa |
| Alternate Name: | Japan Romantic Road |
| Map Custom: | yes |
| Length Km: | 30.2 |
| Length Ref: | [1] |
| Established: | 1953 |
| Direction A: | South |
| Terminus A: | in Karuizawa, Nagano |
| Direction B: | North |
| Terminus B: | in Naganohara, Gunma |
| Previous Type: | Route |
| Previous Route: | 145 |
| Next Type: | Route |
| Next Route: | 147 |
National Route 146 is a national highway of Japan connecting Naganohara, Gunma and Karuizawa, Nagano in Japan, with a total length of 30.2 km (18.77 mi).