Line 1 (Thessaloniki Metro)

Line 1 of the Thessaloniki Metro, also known as the Base Project (Βασικό Έργο), is a deep-level underground rapid transit line in Thessaloniki, Greece, connecting in the west with  in the east, before continuing on to the. The line is set to open in March 2024. Discovery of historical sites in 2019 halted work for 28 months while excavations took place. Of the line's 13 stations, 11 are also stops for Thessaloniki Metro's Line 2, as they will share tunnels. The line is expected to open in 2024.

Construction costs for the line are set at €1.05 billion ($ billion), enough to classify it as a megaproject.