| Country: | POL |
| Type: | DK |
| Route: | 3 |
| Length Km: | 504 |
| Established: | 1986 |
| Regions: | West Pomeranian Voivodeship Lubusz Voivodeship Lower Silesian Voivodeship |
| Cities: | Szczecin, Gorzów Wielkopolski, Zielona Góra, Legnica |
| Map: | Mapa DK3.png |
| Direction A: | north |
| Terminus A: | Świnoujście at the German border |
| Direction B: | south |
| Terminus B: | Jakuszyce at the Czech border |
| Maint: | GDDKiA |
| Previous Type: | DK |
| Previous Route: | 2 |
| Next Type: | DK |
| Next Route: | 4 |
| E-Road: | E65 |
National road 3 (Polish: Droga krajowa nr 3) is a route in the Polish national road network. The highway connects the northwestern and southwestern regions of Poland, running from Świnoujście at the German border to Jakuszyce at the Czech border, traversing through the West Pomeranian, Lubusz and Lower Silesian voivodeships. National road 3 is a component of European highway E65.
National road 3 is currently being upgraded to express road S3, with the older highway being classified as a gmina road, running parallel to or near the completed sections of the modern expressway.