The 1915 Çanakkale Bridge (Turkish: 1915 Çanakkale Köprüsü) is a road suspension bridge in the province of Çanakkale in northwestern Turkey. Situated just south of the coastal towns of Lapseki and Gelibolu, the bridge spans the Dardanelles, about ten kilometres (six miles) south of the Sea of Marmara. The bridge is the longest suspension bridge in the world—with a main span of 2,023 m (2.023 km; 1.257 mi), the bridge surpasses the Akashi Kaikyo Bridge (1998) in Japan by 32 m (105 ft).
The bridge was officially opened by President Recep Tayyip Erdoğan on 18 March 2022 after roughly five years of construction. It is the centrepiece of the planned 321-kilometre-long (199 mi) US$2.8 billion O-6 motorway, which will connect the O-3 and O-7 motorways in East Thrace to the O-5 motorway in Anatolia. The year "1915" in the official Turkish name honours an important Ottoman victory in the Gallipoli campaign comprising an unsuccessful Entente naval attack followed by invasions of the Gallipoli peninsula by the forces of Australia, New Zealand, France, and Great Britain, on 25 April 1915 and a second in August; the Entente land forces failed to make significant progress and were evacuated at the end of that year.