Nishi-ku (西区) is a ward of the city of Sakai in Osaka Prefecture, Japan.
The ward has an area of 28.62 km2 (11.05 sq mi) and a population of 133,583.
The population density is 4,667 per square kilometer.
The wards of Sakai were established when Sakai became a city designated by government ordinance on April 1, 2006.
This Osaka Prefecture location article is a stub.