Omonoia Square (, Plateía Omonoías, , "Concord Square", often simply referred to as Omónoia ) is a central square in Athens. Forming the centre of Omonoia. It marks the northern corner of the downtown area defined by the city plans of the 19th century, and is one of the city's principal traffic hubs. It is served by Omonoia metro station.

Omonoia Square is one of the oldest squares in the city of Athens and an