Suita (吹田市, Suita-shi) is a city located in northern Osaka Prefecture, Japan.As of August 1, 2011, the city has an estimated population of 356,751 and a population density of 9,880 persons per km². The total area is 36.11 km².The city was founded on April 1, 1940, and was the site of Expo '70, a World's Fair held in 1970.