| Country: | CRI |
| Type: | Tertiary |
| Route: | 309 |
| Map Custom: | yes --> |
| Direction A: | NORTH/SOUTH/EAST/WEST? |
| Direction B: | NORTH/SOUTH/EAST/WEST? |
| Terminus B: | --> |
| Provinces: | San José |
| Length Km: | 6.880 |
| Length Round: | 2 |
| Previous Type: | RNT |
| Previous Route: | 308 |
| Next Type: | RNT |
| Next Route: | 310 |
National Tertiary Route 309, or just Route 309 (Spanish; Castilian: Ruta Nacional Terciaria 309, or Spanish; Castilian: Ruta 309) is a National Road Route of Costa Rica, located in the San José province.[1]
In San José province the route covers Vázquez de Coronado canton (Dulce Nombre de Jesús district), Moravia canton (San Jerónimo district).