Agios Stefanos (Greek: Άγιος Στέφανος, romanized: Ágios Stéfanos, meaning Saint Stephen) is a town and a northern suburb of the Athens agglomeration, Greece.

[3] Agios Stefanos is situated in the hills in the northeastern part of the Athens conurbation, at about 350 m elevation.

The source of the river Kifisos is near Agios Stefanos.

Its built-up area is continuous with those of the neighbouring suburbs Anoixi and Stamata to the south.

Athens ERA-1 transmitter, the second tallest man-made structure of Greece, is situated north of Agios Stefanos.