| Demirciköy Tunnel Demirciköy Tüneli | |
| Location: | Sinop, Sinop Province |
| Coordinates: | 41.9439°N 35.0842°W |
| Status: | Operational |
| Operator: | General Directorate of Highways |
| Traffic: | automotive |
| Construction: | Dağcan Construction and Trade Company Inc |
| Length: | 1680and |
| Lanes: | 2 x 2 |
| Speed: | 80km/h |
Demirciköy Tunnel (tr|Demirciköy Tüneli) is a highway tunnel constructed in Sinop Province, northern Turkey.
Demirciköy Tunnel is part of the Sinop-Samsun Highway within the Black Sea Coastal Highway, of which construction was carried out by the Turkish Dağcan Construction and Trade Company Inc. The 1680and-long twin-tube tunnel carrying two lanes of traffic in each direction is flanked by 1285--long Çiftlik Tunnel in the north and 348--long Gerze Tunnel in the south on the same highway.
The tunnel was opened to traffic on 26 March 2014.