Seibu Railway Company, Ltd. is a conglomerate based in Tokorozawa, Saitama, Japan, with principal business areas in railways, tourism, and real estate. Seibu Railway's operations are concentrated in northwest Tokyo and Saitama Prefecture; the name "Seibu" is an abbreviation of "west Musashi", referring to the historic name for this area. It and its holding company hold shares of numerous bus, hotel and tourism operations nationwide.

Tokorozawa is a city located in Saitama Prefecture, Japan. As of 1 February 2024, the city had an estimated population of 343,298 in 168,939 households and a population density of 4761 persons per km². The total area of the city is 72.11 square kilometres (27.84 sq mi).