The Hejaz (also Hedjaz) Railway (Turkish: Hicaz Demiryolu) was a narrow gauge railway that ran from Damascus to Medina, through the Hejaz region of Saudi Arabia, with a branch line to Haifa on the Mediterranean Sea. It was a part of the Ottoman railway network and was built to extend the line from the Haydarpaşa Terminal in Istanbul beyond Damascus to the holy city of Mecca. It got no further than Medina, 400 kilometres (250 mi) short of Makkah, due to the interruption of the construction works caused by the outbreak of World War I. Damascus to Medina is 1,300 kilometres (810 mi).
The main purpose of the railway was to establish a connection between Constantinople, the capital of the Ottoman Empire and the seat of the Islamic Caliphate, and Hejaz in Arabia, the site of the holiest shrines of Islam and the holy city of Mecca, the destination of the Hajj annual pilgrimage. Another important reason was to improve the economic and political integration of the distant Arabian provinces into the Ottoman state, and to facilitate the transportation of military forces.
The railway is remarkable both for having had no debt when completed and for having many miles of track below sea level.