Totsuka-ku (戸塚区) is one of the 18 wards of the city of Yokohama in Kanagawa Prefecture, Japan. As of 2010, the ward had an estimated population of 273,418 and a density of 7,640 persons per km². The total area was 35.70 km². Totsuka Ward is located in eastern Kanagawa Prefecture, and in the center-western area of the city of Yokohama. The area is largely flatland, with scattered small hills. The Kashio River passes through the Ward.
Totsuka Ward is largely a regional commercial center and bedroom community for central Yokohama and Tokyo. Totsuka retains a relatively strong industrial base. In 2010, 160 factories in the ward employed 12,010 employees and their shipment amounted to 399 billion yen. There are major factories operated by KI Holdings, Hitachi Ltd., Nissin Foods, Yamazaki Baking Company Limited, Pola Cosmetics, and others.