Chaidari (Greek, modern: Χαϊδάρι, Ancient/Katharevousa: Χαϊδάριον), is a suburb in the west northwestern part of Athens, Greece. The two mountaintops of Aigaleo lies to the north and south. It is also located SE of Eleusis, S of the Attiki Odos (number 6), W of Kifissou Avenue (GR-1/E75, and Athens, NW of Poseidonos Avenue and N of Piraeus.
The eastern portion of Chaidari was mainly made up of farmlands. Pasture farming was common. Urban development replaced much of the farmlands between the 1950s and the 1980s. Today, the eastern half of the municipality is urbanized or residential. The rocky landscape of Aigaleo with a few bushes lies to the north and northwest. The pine forests of Dafni along with a monastery and a forest park lie to the west and the southwest.
The Haidari concentration camp (Greek: στρατόπεδο συγκέντρωσης Χαϊδαρίου, stratópedo syngéntrosis Chaidaríou, German: KZ Chaidari) was a concentration camp operated by the German Schutzstaffel in Haidari during the Axis Occupation of Greece from September 1943 to September 1944.