|Regional unit||West Attica|
|o Municipal unit||1.400 km2 (0.541 sq mi)|
|Elevation||150 m (490 ft)|
|o Municipal unit||9,454|
|o Municipal unit density||6,800/km2 (17,000/sq mi)|
|Time zone||UTC+2 (EET)|
Zefyri (Greek: ) 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 km2.
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 Motorway 6 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 Piraeus-Patras railway and the new Athens Airport-Patras railway pass through Zefyri.
The earthquake of 7 September 1999 damaged some tens of homes.