Panionios G.S.S. Football Club, the Pan-Ionian Gymnastics Club of Smyrna, more commonly known as Panionios F.C. or simply Panionios, is a Greek football club based in Nea Smyrni, a suburban town in the Athens agglomeration, Greece. Part of Panionios G.S.S., Panionios F.C. is the oldest Greek football club.

Nea Smyrni is a municipality and a town in South Athens, Greece. At the 2021 census, it had 72,853 inhabitants. It was named after the former Greek city Smyrna, whence many refugees arrived and settled in the Nea Smyrni area following the 1922 catastrophe of Asia Minor and the Great fire of Smyrna, as a result of the Greco-Turkish war.