Kōza District (高座郡 Kōza-gun) is a district located in central Kanagawa Prefecture, Japan. It currently consists of only one town, Samukawa. The entire cities of Chigasaki, Fujisawa, Yamato, Ayase, Ebina, Zama; and parts of the city of Sagamihara, were formerly part of Kōza District. As of 2009, the district has an estimated population of 47,812 and a density of 3,560 persons per km². The total area is 13.42 km².