Nikaia (Greek: Νίκαια, Níkaia), known before 1940 as Kokkinia (Κοκκινιά, Kokkiniá),[2] is a town and a suburb of the Piraeus agglomeration, in the southwestern part of the Athens urban area, Greece.

According to the station of the National Observatory of Athens Nikaia has a hot semi-arid climate (Köppen climate classification: BSh) with mild winters and hot summers.

It was the largest Nazi roundup and one of the largest-scale war crimes perpetrated during the German occupation of Greece.

Nikaia, like many other places around Greece, owes its population eruption to Greek refugees who were forced out of Asia Minor after the 1919-1922 Greco-Turkish war ended.

The Greek Weightlifting Grand Prix took place in Nikaia on December 9 and 10, 2003.