Type Deep Level Termini Alsos VeikouGoudi Daily ridership 530,000 (estimated) | System Athens Metro Stations 14 | |
Status Proposed/Construction approved Similar Jurong Region MRT Line, Purple Line Extension, Chūō Shinkansen |

Line 4 of the Athens Metro is a future line that will run from Alsos Veikou to Goudi. Construction of the line was approved on 25 September 2014 and it is scheduled to begin in 2016.
Line 4 has been under consideration for many years and apart from that, it has also been a promise of most politicians. Its exact route was changed multiple times. One of the most famous routes was the U-shaped line from Perissos to Katehaki (which are current stations of lines 1 and 3 respectively), including a branch to Vyronas. However, the route from Alsos Veikou to Goudi was chosen, as it has the benefit of being the one passing from the densely populated areas of central Athens, like Galatsi, Exarheia, Kolonaki, Kaisariani and Zografou.
In the long future, it will be extender further north to Ethniki Odos and to other important suburbs of Athens, like Marousi.
Stations
As of June 2016, the proposed route for the first phase of Line 4 is:
Planned