Line 2 of the Thessaloniki Metro, also known as the Kalamaria Extension (Greek: Επέκταση Καλαμαριάς), is a deep-level underground rapid transit line in Thessaloniki, Greece, connecting New Railway Station in the west with Mikra in the south-east.

The section of the line between New Railway Station and 25 Martiou stations was set to open in 2023, with the rest of the line becoming operational in 2024.

[1] This was delayed to opening in 2025, after inauguration of Line 1 the prior year.

[6] 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 Mikra, the eastern terminus of Line 2.