Niiza (新座市 Niiza-shi?) is a city located in Saitama Prefecture, Japan, and is essentially a suburb of the Tokyo conurbation. Niiza is located at the southernmost part of Saitama.The city was founded on November 1, 1970. As of 2010, the city has an estimated population of 159,741 and a population density of 7,010 persons per km². The total area is 22.80 km².