| Country: | NOR |
| Type: | Fylkesvei |
| Route: | 420 |
| Map Custom: | yes |
| Length Km: | 63.8 |
| Direction A: | North |
| Terminus A: | in Moland, Arendal |
| Junction: | |
| Direction B: | South |
| Terminus B: | in Sørlandsparken, Kristiansand |
| Previous Type: | fylkesvei |
| Previous Route: | 419 |
| Next Type: | fylkesvei |
| Next Route: | 421 |
Norwegian County Road 420 is a Norwegian county road in Agder county, Norway. The 63.8km (39.6miles) long road runs along the coast from the European route E18 highway at the Sørlandsparken in Kristiansand in the southwest to the European route E18 at Moland in Arendal.[1]