The Selçukgazi Tunnel (Turkish: Selçukgazi Tüneli) is a motorway tunnel located at Dürdane Hill in Marmara Region as part of the Istanbul-Bursa Motorway O-5 in Turkey.

[1] Situated near Selçukgazi village in Osmangazi district between Gemlik and Bursa, it is a twin-tube tunnel of 1,192 and 1,303 m (3,911 and 4,275 ft).

[2][3] The construction is carried out by Otoyol A.Ş., a consortium of Turkish Nurol, Özaltın, Makyol, Yüksel, Göçay and Italian Astaldi companies.

[4] In March 2014, it was announced that the preparatory works are completed and tunneling will start soon.

[5] The tunnel was opened to traffic on March 12, 2017 by Turkish Prime Minister Binali Yıldırım.