Line 2 of the Thessaloniki Metro, also known as the Kalamaria Extension (), 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 2026, after inauguration of Line 1. 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 and Mikra) are set at â¬518 million ($ million).
Line 2 is to be extended further, with an eastern extension towards Thessaloniki Airport (4 stations) and a loop extension in the west (9 stations). A priority for Elliniko 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.