Setagaya (世田谷区, Setagaya-ku) is a special ward located in Tokyo Metropolis, Japan. It is also the name of a neighborhood within the ward. The ward calls itself Setagaya City in English. Its official bird is the Azure-winged Magpie, its flower the Fringed Orchid, and its tree the Zelkova serrata. It has the largest population and second largest area (after Ōta) of Tokyo's 23 special wards.
As of May 1, 2011, the ward has an estimated population of 837,185 and a population density of 14,414.34 persons per km². The total area is 58.08 km², the largest of the 23 special wards. Setagaya sits at the southwestern corner of the 23 special wards. The Tama River separates it from Kanagawa Prefecture. Most of the land is in the Musashino tableland. The parts along the Tama River to the south are comparatively low-lying.