Warabi, city, Saitama ken (prefecture), Honshu, Japan. It lies on the alluvial plain of the Ara River. An early post town, it has long been a centre of cotton fabric manufacture. The city was linked to a major railway in 1899, and urbanization developed after World War II. Low rice paddies have been reclaimed to accommodate the growing number of factories and dwellings. The city’s woolen textile and electric industries are relatively large. Warabi is now a suburb of the Tokyo-Yokohama metropolitan area, with a rapidly increasing commuter population. Pop. (2005) 70,010; (2010) 71,502.