Seibu Holdings, Inc. is a Japanese holding company that primarily owns Seibu Railway, Prince Hotels, and Seibu Bus and its subsidiaries, which are collectively known as the Seibu Group . In total, fifty-three companies across the world are affiliated with the Seibu Group. The company was formed in 2006 to restructure the group after it had come to light in 2004 that the predecessor to Seibu Holdings, Kokudo, had falsified the ownership of its shares in Seibu Railway for over forty years.

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.