Zefyri () is a suburb of Athens and former municipality in West Attica, Greece. Since the 2011 local government reform it is part of the municipality Fyli, of which it is a municipal unit. The municipal unit has an area of 1.400 km<sup>2</sup>.
Zefyri is situated near the northeastern end of the Aigaleo mountains. Its built-up area is continuous with those of the neighbouring suburbs Ano Liosia, Acharnes and Kamatero. The A6 motorway passes through Zefyri, by the 440 m cut and cover Zefyri Tunnel. Zefyri is 2 km southeast of Ano Liosia, 2 km southwest of Acharnes and about 10 km north of Athens city centre. The old metric PiraeusâÂÂPatras railway and the new Athens AirportâÂÂPatras railway pass through Zefyri.
The earthquake of 7 September 1999 damaged some tens of homes.