Inaugurated in 1930, the current Omonia station replaced the original station, built in 1895, which was located further to the south at the junction of Athinas and Lykourgou Streets.  Situated beneath Omonia Square, this served as the north terminal until 1948, when the electric subway extension to the north was released.  At that time, the south terminal was located in Piraeus.  The old station on Athinas street is now covered, used by the Company as a train depot, with the Athens-Pireaeus, Electric Railway Company headquarters being built over it.

Today, the old Electric Subway station, servicing metro line 1, has been entirely reconstructed.  However, by preserving many of its old decorations and architectural elements, it has been classified as a listed building. The newer, modern station of metro line 2, is located at a lower level.  Built in 2000, its interior is decorated with the works of Greek artists, like the “Footballers” by Pavlos, and the “Queue” by Nikos Kessanlis.