Line 2 (Thessaloniki Metro)

Line 2 of the Thessaloniki Metro, also known as the Kalamaria Extension (Επέκταση Καλαμαριάς), is a deep-level underground rapid transit line in Thessaloniki, Greece, connecting in the west with  in the south-east. The section of the line between and  stations was set to open in 2023, with the rest of the line becoming operational in 2024. This was delayed to opening in 2025, after inauguration of Line 1 the prior year. Of the line's 16 stations, 11 are also stops for Thessaloniki Metro's Line 1, as they will share tunnels.

Construction costs for the line (between Nomarhia and Mikra) are set at €518 million ($ million).

Line 2 is to be extended further, with an eastern extension towards Macedonia International Airport (4 stations) and a loop extension in the west (9 stations). A priority for Attiko Metro S.A., the company overseeing construction, is the western extension. This is so as to provide access to the metro to working class suburbs, since the airport will be serviced by a 10-minute shuttle bus to, the eastern terminus of Line 2. Originally the two extensions were to be separate lines, but they were merged into a single circular line in 2018.